How to play
Switch into a predicted Water attack to activate Storm Drain, then attack or use Recover. Storm Drain grants Water immunity and raises Special Attack when hit by Water moves.
POKÉDEX #423 · GENERATION 4
Gastrodon Build Guide
WaterGround
Bulky special attacker and recovery support
Build a team with Gastrodon ↓Starter moveset
Generation 9 · casual singles · base form
ITEMLeftovers
ABILITYStorm Drain
NATURECalm
1
Earth Power
2
Surf
3
Ice Beam
4
Recover
Watch out for
Grass attacks deal 4× damage. Its low Speed makes it vulnerable to strong attackers, and Storm Drain does not protect against Grass coverage.
About this example
This editorial starting point is not a ranked-format recommendation or a legality check. It does not specify EVs or Tera type. Moves, items and abilities here do not change the builder score.
Teammate ideas
A Steel/Flying or Fire teammate can resist Grass attacks. Add a faster attacker to complement its low Speed.
Corviknight
Resists Grass attacks and is immune to Ground.
Charizard
Resists Grass; Gastrodon covers Electric and resists Rock.
These are typing-based starting pairs, not a complete competitive team. Check the remaining four slots and your game’s rules.
Compare computed teammate suggestions →Alternative: Quagsire
Quagsire shares Water/Ground typing but uses different abilities and an alternative defensive role.
Try Quagsire →Type matchups
Weak to
Grass4×
Resistances and immunities
Fire0.5×Electric0×Poison0.5×Rock0.5×Steel0.5×
Typing only. Abilities, items and battle effects can change these matchups.
HP111
Attack83
Defense68
Sp. Attack92
Sp. Defense82
Speed39
Evolution chain
- Shellos#422
Level 30
Gastrodon#423
Standard main-series evolution conditions. Regional forms and games with special evolution systems can differ.
Build your Gastrodon team
Start with Gastrodon. Add teammates and compare your type-and-base-stat score.
Gen 9 · National Dex · Casual Settings & scope
Format scope · casual planning
Base species #001–1025, using Generation 9 data. A casual planning pool, not a VGC, ranked, or Showdown National Dex legality validator. Regional, Mega and alternate forms are not included yet.
Gastrodon
WaterGroundUnderstand your team
Offense80
Defense67
Coverage33
Synergy8
Types & base stats only · Not a win probability.
Saved teams · 0
Keep up to 20 teams in this browser. Clearing browser data removes saved teams.
No saved teams yet.
FIND A BETTER FIT
Recommended Pokémon
Fill your empty slots first. Each candidate is scored using the same rules as your current team. Only positive score changes are shown.
+31 pts
Escavalier
BugSteel
Team score 50 → 81
Why this Pokémon?
- Adds Grass resistance or immunity
- Adds super-effective coverage against Grass, Ice, Psychic and more
- Defense 67 → 85
+30 pts
Skarmory
Steel
Team score 50 → 80
Why this Pokémon?
- Adds Grass resistance or immunity
- Adds super-effective coverage against Grass, Ice, Fighting and more
- Defense 67 → 88
+30 pts
Durant
BugSteel
Team score 50 → 80
Why this Pokémon?
- Adds Grass resistance or immunity
- Adds super-effective coverage against Grass, Ice, Psychic and more
- Defense 67 → 85
+30 pts
Corviknight
Steel
Team score 50 → 80
Why this Pokémon?
- Adds Grass resistance or immunity
- Adds super-effective coverage against Grass, Ice, Fighting and more
- Defense 67 → 88
+29 pts
Forretress
BugSteel
Team score 50 → 79
Why this Pokémon?
- Adds Grass resistance or immunity
- Adds super-effective coverage against Grass, Ice, Psychic and more
- Defense 67 → 85
+29 pts
Scizor
BugSteel
Team score 50 → 79
Why this Pokémon?
- Adds Grass resistance or immunity
- Adds super-effective coverage against Grass, Ice, Psychic and more
- Defense 67 → 85
Suggestions optimize this initial planning heuristic. Your preferences and actual battle strategy may favor another Pokémon.
Key insights
- Grass attacks threaten 1 of 1 teammates, with no teammate resisting them by type.
- Gastrodon takes 4× damage from Grass attacks by type.
- Your own types can hit 6 of 18 single-type targets super effectively. Actual move coverage can differ.
- No teammate has a base Speed of 100 or higher. Consider adding a faster option.
Detailed type analysis · all 18 types
Incoming damage assumes typing only. 0× = immune, ½× / ¼× = resistant, 2× / 4× = weak. Resistance counts include immunities.
| Attack | Gastrodon | Weak | Resist |
|---|---|---|---|
| Normal | 1× | 0 | 0 |
| Fire | ½× | 0 | 1 |
| Water | 1× | 0 | 0 |
| Electric | 0× | 0 | 1 |
| Grass | 4× | 1 | 0 |
| Ice | 1× | 0 | 0 |
| Fighting | 1× | 0 | 0 |
| Poison | ½× | 0 | 1 |
| Ground | 1× | 0 | 0 |
| Flying | 1× | 0 | 0 |
| Psychic | 1× | 0 | 0 |
| Bug | 1× | 0 | 0 |
| Rock | ½× | 0 | 1 |
| Ghost | 1× | 0 | 0 |
| Dragon | 1× | 0 | 0 |
| Dark | 1× | 0 | 0 |
| Steel | ½× | 0 | 1 |
| Fairy | 1× | 0 | 0 |
Offensive type coverage
Against single-type targets, using only same-type attacks. This is not coverage against every dual-type species.
NormalNeutral
Fire✓ Super effective
WaterNeutral
Electric✓ Super effective
GrassResisted
IceNeutral
FightingNeutral
Poison✓ Super effective
Ground✓ Super effective
FlyingNeutral
PsychicNeutral
BugNeutral
Rock✓ Super effective
GhostNeutral
DragonNeutral
DarkNeutral
Steel✓ Super effective
FairyNeutral
How is the score calculated?
Offense (25%): neutral-or-better type coverage and strongest attacking base stats. Defense (30%): team resistances, unprotected and repeated weaknesses, and 4× vulnerabilities. Coverage (25%): fraction of 18 single-type targets hit super effectively by your own types. Synergy (20%): teammates resisting each other’s weaknesses, physical/special/bulk stat signals and base Speed ≥100. Scores are rounded to 0–100; the total uses the displayed subscores.
Rating bands: Excellent ≥80, Good ≥65, Fair ≥45, Poor below 45. An empty team has no rating.
Small teams are provisional and are not given a separate completion bonus. Adding a Pokémon can lower the score if it creates new weaknesses or lowers averages. These initial heuristics have not been calibrated against battle outcomes.
Data: Pokémon Showdown / @pkmn/dex · Sprites: PokéAPI contributors · Base species only
Sources & guide notes
Starter advice written for this guide; mechanics checked against Pokémon Showdown’s Generation 9 data.
- Smogon: format-specific strategy
- Pokémon Database: moves and evolution
- Pokémon Showdown mechanics data
Reviewed October 6, 2026. Suggest a correction.