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Gastrodon

#342 in the Ultra Sun & Ultra Moon Pokédex • Sea Slug Pokémon

Ultra Sun

Long ago, it had a shell on its back. There’s now a vestigial plate on its back that’s hard but thin.

Ultra Moon

Their shape and color change, depending on their environment and diet. There are many of them at beaches where the waves are calm.

Pokédexes

Updated Poni #89Updated Alola #342

Egg Group

Water 1Amorphous

Steps to Hatch

5,120

Effort Values Yielded

2 HP

Gender Ratio

50% male / 50% female

Capture Rate

75

Base Experience

166
PokémonRequiresEvolution
Shellos

Shellos

#341

Level 30

Gastrodon

Gastrodon

#342

Ultra Moon

LocationMethodLevelChanceConditions

Ancient Poni Path

Surfing41-4420%

-

Ancient Poni Path

Walking in tall grass or a cave41-4410%

-

Exeggutor Island

Walking in tall grass or a cave42-4510%

-

Poni Breaker Coast

Surfing41-4420%

-

Poni Wilds

Walking in tall grass or a cave41-4410%

-

Ultra Sun

LocationMethodLevelChanceConditions

Ancient Poni Path

Surfing41-4420%

-

Ancient Poni Path

Walking in tall grass or a cave41-4410%

-

Exeggutor Island

Walking in tall grass or a cave42-4510%

-

Poni Breaker Coast

Surfing41-4420%

-

Poni Wilds

Walking in tall grass or a cave41-4410%

-

Shellos

Drifloon

Gastrodon normal sprite

Normal

Shiny Gastrodon sprite

Shiny

Gastrodon

Sea Slug Pokémon

#342
WaterGround

Height

0.9 m

Weight

29.9 kg

Base XP

166

Abilities

Sticky HoldStorm DrainSand Force

HP

111

Attack

83

Defense

68

Sp. Atk

92

Sp. Def

82

Speed

39

Total

475

Type Chart

Weaknesses

Takes 4× from

Grass

Resistances

Takes 0× from

Electric

Takes 0.5× from

FirePoisonRockSteel
Class
Description
StartHardenNormalStatus--30

The user stiffens all the muscles in its body to raise its Defense stat.

StartMud-SlapGroundSpecial2010010

The user hurls mud in the target’s face to inflict damage and lower its accuracy.

StartMud SportGroundStatus--15

The user kicks up mud on the battlefield. This weakens Electric-type moves for five turns.

StartWater PulseWaterSpecial6010020

The user attacks the target with a pulsing blast of water. This may also confuse the target.

2Mud SportGroundStatus--15

The user kicks up mud on the battlefield. This weakens Electric-type moves for five turns.

4HardenNormalStatus--30

The user stiffens all the muscles in its body to raise its Defense stat.

7Water PulseWaterSpecial6010020

The user attacks the target with a pulsing blast of water. This may also confuse the target.

11Mud BombGroundSpecial658510

The user launches a hard-packed mud ball to attack. This may also lower the target’s accuracy.

16Hidden PowerNormalSpecial6010015

A unique attack that varies in type depending on the Pokémon using it.

22Rain DanceWaterStatus--5

The user summons a heavy rain that falls for five turns, powering up Water-type moves. It lowers the power of Fire-type moves.

29Body SlamNormalPhysical8510015

The user drops onto the target with its full body weight. This may also leave the target with paralysis.

41Muddy WaterWaterSpecial908510

The user attacks by shooting muddy water at the opposing Pokémon. This may also lower their accuracy.

54RecoverNormalStatus--5

Restoring its own cells, the user restores its own HP by half of its max HP.

Class
Description
TM06ToxicPoisonStatus-9010

A move that leaves the target badly poisoned. Its poison damage worsens every turn.

TM07HailIceStatus--10

The user summons a hailstorm lasting five turns. It damages all Pokémon except the Ice type.

TM10Hidden PowerNormalSpecial6010015

A unique attack that varies in type depending on the Pokémon using it.

TM13Ice BeamIceSpecial9010010

The target is struck with an icy-cold beam of energy. This may also leave the target frozen.

TM14BlizzardIceSpecial110705

A howling blizzard is summoned to strike opposing Pokémon. This may also leave the opposing Pokémon frozen.

TM15Hyper BeamNormalSpecial150905

The target is attacked with a powerful beam. The user can’t move on the next turn.

TM17ProtectNormalStatus--10

Enables the user to evade all attacks. Its chance of failing rises if it is used in succession.

TM18Rain DanceWaterStatus--5

The user summons a heavy rain that falls for five turns, powering up Water-type moves. It lowers the power of Fire-type moves.

TM21FrustrationNormalPhysical-10020

This full-power attack grows more powerful the less the user likes its Trainer.

TM26EarthquakeGroundPhysical10010010

The user sets off an earthquake that strikes every Pokémon around it.

TM27ReturnNormalPhysical-10020

This full-power attack grows more powerful the more the user likes its Trainer.

TM32Double TeamNormalStatus--15

By moving rapidly, the user makes illusory copies of itself to raise its evasiveness.

TM34Sludge WavePoisonSpecial9510010

The user strikes everything around it by swamping the area with a giant sludge wave. This may also poison those hit.

TM36Sludge BombPoisonSpecial9010010

Unsanitary sludge is hurled at the target. This may also poison the target.

TM37SandstormRockStatus--10

A five-turn sandstorm is summoned to hurt all combatants except the Rock, Ground, and Steel types. It raises the Sp. Def stat of Rock types.

TM39Rock TombRockPhysical609515

Boulders are hurled at the target. This also lowers the target’s Speed stat by preventing its movement.

TM42FacadeNormalPhysical7010020

This attack move doubles its power if the user is poisoned, burned, or paralyzed.

TM44RestPsychicStatus--5

The user goes to sleep for two turns. This fully restores the user’s HP and heals any status conditions.

TM45AttractNormalStatus-10015

If it is the opposite gender of the user, the target becomes infatuated and less likely to attack.

TM48RoundNormalSpecial6010015

The user attacks the target with a song. Others can join in the Round to increase the power of the attack.

TM55ScaldWaterSpecial8010015

The user shoots boiling hot water at its target. This may also leave the target with a burn.

TM68Giga ImpactNormalPhysical150905

The user charges at the target using every bit of its power. The user can’t move on the next turn.

TM71Stone EdgeRockPhysical100805

The user stabs the target from below with sharpened stones. Critical hits land more easily.

TM78BulldozeGroundPhysical6010020

The user strikes everything around it by stomping down on the ground. This lowers the Speed stat of those hit.

TM80Rock SlideRockPhysical759010

Large boulders are hurled at the opposing Pokémon to inflict damage. This may also make the opposing Pokémon flinch.

TM83InfestationBugSpecial2010020

The target is infested and attacked for four to five turns. The target can’t flee during this time.

TM87SwaggerNormalStatus-8515

The user enrages and confuses the target. However, this also sharply raises the target’s Attack stat.

TM88Sleep TalkNormalStatus--10

While it is asleep, the user randomly uses one of the moves it knows.

TM90SubstituteNormalStatus--10

The user makes a copy of itself using some of its HP. The copy serves as the user’s decoy.

TM94SurfWaterSpecial9010015

The user attacks everything around it by swamping its surroundings with a giant wave.

TM98WaterfallWaterPhysical8010015

The user charges at the target and may make it flinch.

TM100ConfideNormalStatus--20

The user tells the target a secret, and the target loses its ability to concentrate. This lowers the target’s Sp. Atk stat.

Class
Description
BlockNormalStatus--5

The user blocks the target’s way with arms spread wide to prevent escape.

Earth PowerGroundSpecial9010010

The user makes the ground under the target erupt with power. This may also lower the target’s Sp. Def stat.

Icy WindIceSpecial559515

The user attacks with a gust of chilled air. This also lowers the opposing Pokémon’s Speed stats.

Pain SplitNormalStatus--20

The user adds its HP to the target’s HP, then equally shares the combined HP with the target.

SnoreNormalSpecial5010015

This attack can be used only if the user is asleep. The harsh noise may also make the target flinch.

Stomping TantrumGroundPhysical7510010

Driven by frustration, the user attacks the target. If the user’s previous move has failed, the power of this move doubles.

Water PulseWaterSpecial6010020

The user attacks the target with a pulsing blast of water. This may also confuse the target.

Sticky Hold

Ability Slot 1

Items held by the Pokémon are stuck fast and cannot be removed by other Pokémon.

Prevents a held item from being removed by other Pokémon.

Storm Drain

Ability Slot 2

Draws in all Water-type moves. Instead of being hit by Water-type moves, it boosts its Sp. Atk.

Redirects single-target Water moves to this Pokémon where possible. Absorbs Water moves, raising Special Attack one stage.

Sand Force

Hidden Ability

Boosts the power of Rock-, Ground-, and Steel-type moves in a sandstorm.

Strengthens Rock, Ground, and Steel moves to 1.3× their power during a sandstorm. Protects against sandstorm damage.

Dittobase

© 2026 dittobase.com. All rights reserved.

This website is an independent platform and is not associated with, validated, backed, or sponsored by Nintendo, Game Freak, Niantic, or The Pokémon Company.

USUM / Pokédex

Gastrodon

Gastrodon

#342 in the Ultra Sun & Ultra Moon Pokédex • Sea Slug Pokémon

Ultra Sun

Long ago, it had a shell on its back. There’s now a vestigial plate on its back that’s hard but thin.

Ultra Moon

Their shape and color change, depending on their environment and diet. There are many of them at beaches where the waves are calm.

Pokédexes

Updated Poni #89Updated Alola #342

Egg Group

Water 1Amorphous

Steps to Hatch

5,120

Effort Values Yielded

2 HP

Gender Ratio

50% male / 50% female

Capture Rate

75

Base Experience

166
PokémonRequiresEvolution
Shellos

Shellos

#341

Level 30

Gastrodon

Gastrodon

#342

Ultra Moon

LocationMethodLevelChanceConditions

Ancient Poni Path

Surfing41-4420%

-

Ancient Poni Path

Walking in tall grass or a cave41-4410%

-

Exeggutor Island

Walking in tall grass or a cave42-4510%

-

Poni Breaker Coast

Surfing41-4420%

-

Poni Wilds

Walking in tall grass or a cave41-4410%

-

Ultra Sun

LocationMethodLevelChanceConditions

Ancient Poni Path

Surfing41-4420%

-

Ancient Poni Path

Walking in tall grass or a cave41-4410%

-

Exeggutor Island

Walking in tall grass or a cave42-4510%

-

Poni Breaker Coast

Surfing41-4420%

-

Poni Wilds

Walking in tall grass or a cave41-4410%

-

Shellos

Drifloon

Gastrodon normal sprite

Normal

Shiny Gastrodon sprite

Shiny

Gastrodon

Sea Slug Pokémon

#342
WaterGround

Height

0.9 m

Weight

29.9 kg

Base XP

166

Abilities

Sticky HoldStorm DrainSand Force

HP

111

Attack

83

Defense

68

Sp. Atk

92

Sp. Def

82

Speed

39

Total

475

Type Chart

Weaknesses

Takes 4× from

Grass

Resistances

Takes 0× from

Electric

Takes 0.5× from

FirePoisonRockSteel
Class
Description
StartHardenNormalStatus--30

The user stiffens all the muscles in its body to raise its Defense stat.

StartMud-SlapGroundSpecial2010010

The user hurls mud in the target’s face to inflict damage and lower its accuracy.

StartMud SportGroundStatus--15

The user kicks up mud on the battlefield. This weakens Electric-type moves for five turns.

StartWater PulseWaterSpecial6010020

The user attacks the target with a pulsing blast of water. This may also confuse the target.

2Mud SportGroundStatus--15

The user kicks up mud on the battlefield. This weakens Electric-type moves for five turns.

4HardenNormalStatus--30

The user stiffens all the muscles in its body to raise its Defense stat.

7Water PulseWaterSpecial6010020

The user attacks the target with a pulsing blast of water. This may also confuse the target.

11Mud BombGroundSpecial658510

The user launches a hard-packed mud ball to attack. This may also lower the target’s accuracy.

16Hidden PowerNormalSpecial6010015

A unique attack that varies in type depending on the Pokémon using it.

22Rain DanceWaterStatus--5

The user summons a heavy rain that falls for five turns, powering up Water-type moves. It lowers the power of Fire-type moves.

29Body SlamNormalPhysical8510015

The user drops onto the target with its full body weight. This may also leave the target with paralysis.

41Muddy WaterWaterSpecial908510

The user attacks by shooting muddy water at the opposing Pokémon. This may also lower their accuracy.

54RecoverNormalStatus--5

Restoring its own cells, the user restores its own HP by half of its max HP.

Class
Description
TM06ToxicPoisonStatus-9010

A move that leaves the target badly poisoned. Its poison damage worsens every turn.

TM07HailIceStatus--10

The user summons a hailstorm lasting five turns. It damages all Pokémon except the Ice type.

TM10Hidden PowerNormalSpecial6010015

A unique attack that varies in type depending on the Pokémon using it.

TM13Ice BeamIceSpecial9010010

The target is struck with an icy-cold beam of energy. This may also leave the target frozen.

TM14BlizzardIceSpecial110705

A howling blizzard is summoned to strike opposing Pokémon. This may also leave the opposing Pokémon frozen.

TM15Hyper BeamNormalSpecial150905

The target is attacked with a powerful beam. The user can’t move on the next turn.

TM17ProtectNormalStatus--10

Enables the user to evade all attacks. Its chance of failing rises if it is used in succession.

TM18Rain DanceWaterStatus--5

The user summons a heavy rain that falls for five turns, powering up Water-type moves. It lowers the power of Fire-type moves.

TM21FrustrationNormalPhysical-10020

This full-power attack grows more powerful the less the user likes its Trainer.

TM26EarthquakeGroundPhysical10010010

The user sets off an earthquake that strikes every Pokémon around it.

TM27ReturnNormalPhysical-10020

This full-power attack grows more powerful the more the user likes its Trainer.

TM32Double TeamNormalStatus--15

By moving rapidly, the user makes illusory copies of itself to raise its evasiveness.

TM34Sludge WavePoisonSpecial9510010

The user strikes everything around it by swamping the area with a giant sludge wave. This may also poison those hit.

TM36Sludge BombPoisonSpecial9010010

Unsanitary sludge is hurled at the target. This may also poison the target.

TM37SandstormRockStatus--10

A five-turn sandstorm is summoned to hurt all combatants except the Rock, Ground, and Steel types. It raises the Sp. Def stat of Rock types.

TM39Rock TombRockPhysical609515

Boulders are hurled at the target. This also lowers the target’s Speed stat by preventing its movement.

TM42FacadeNormalPhysical7010020

This attack move doubles its power if the user is poisoned, burned, or paralyzed.

TM44RestPsychicStatus--5

The user goes to sleep for two turns. This fully restores the user’s HP and heals any status conditions.

TM45AttractNormalStatus-10015

If it is the opposite gender of the user, the target becomes infatuated and less likely to attack.

TM48RoundNormalSpecial6010015

The user attacks the target with a song. Others can join in the Round to increase the power of the attack.

TM55ScaldWaterSpecial8010015

The user shoots boiling hot water at its target. This may also leave the target with a burn.

TM68Giga ImpactNormalPhysical150905

The user charges at the target using every bit of its power. The user can’t move on the next turn.

TM71Stone EdgeRockPhysical100805

The user stabs the target from below with sharpened stones. Critical hits land more easily.

TM78BulldozeGroundPhysical6010020

The user strikes everything around it by stomping down on the ground. This lowers the Speed stat of those hit.

TM80Rock SlideRockPhysical759010

Large boulders are hurled at the opposing Pokémon to inflict damage. This may also make the opposing Pokémon flinch.

TM83InfestationBugSpecial2010020

The target is infested and attacked for four to five turns. The target can’t flee during this time.

TM87SwaggerNormalStatus-8515

The user enrages and confuses the target. However, this also sharply raises the target’s Attack stat.

TM88Sleep TalkNormalStatus--10

While it is asleep, the user randomly uses one of the moves it knows.

TM90SubstituteNormalStatus--10

The user makes a copy of itself using some of its HP. The copy serves as the user’s decoy.

TM94SurfWaterSpecial9010015

The user attacks everything around it by swamping its surroundings with a giant wave.

TM98WaterfallWaterPhysical8010015

The user charges at the target and may make it flinch.

TM100ConfideNormalStatus--20

The user tells the target a secret, and the target loses its ability to concentrate. This lowers the target’s Sp. Atk stat.

Class
Description
BlockNormalStatus--5

The user blocks the target’s way with arms spread wide to prevent escape.

Earth PowerGroundSpecial9010010

The user makes the ground under the target erupt with power. This may also lower the target’s Sp. Def stat.

Icy WindIceSpecial559515

The user attacks with a gust of chilled air. This also lowers the opposing Pokémon’s Speed stats.

Pain SplitNormalStatus--20

The user adds its HP to the target’s HP, then equally shares the combined HP with the target.

SnoreNormalSpecial5010015

This attack can be used only if the user is asleep. The harsh noise may also make the target flinch.

Stomping TantrumGroundPhysical7510010

Driven by frustration, the user attacks the target. If the user’s previous move has failed, the power of this move doubles.

Water PulseWaterSpecial6010020

The user attacks the target with a pulsing blast of water. This may also confuse the target.

Sticky Hold

Ability Slot 1

Items held by the Pokémon are stuck fast and cannot be removed by other Pokémon.

Prevents a held item from being removed by other Pokémon.

Storm Drain

Ability Slot 2

Draws in all Water-type moves. Instead of being hit by Water-type moves, it boosts its Sp. Atk.

Redirects single-target Water moves to this Pokémon where possible. Absorbs Water moves, raising Special Attack one stage.

Sand Force

Hidden Ability

Boosts the power of Rock-, Ground-, and Steel-type moves in a sandstorm.

Strengthens Rock, Ground, and Steel moves to 1.3× their power during a sandstorm. Protects against sandstorm damage.

Dittobase

© 2026 dittobase.com. All rights reserved.

This website is an independent platform and is not associated with, validated, backed, or sponsored by Nintendo, Game Freak, Niantic, or The Pokémon Company.