Crimson Blaze

Basic

{Water} Tackle 10

Weakness {Lightning} +20

Retreat {Colorless}

Shellder

Celestial Guardians

Genetic Apex

{Water} Tongue Slap 20

Weakness {Lightning} +20

Retreat {Colorless}

{Water}{Water} Shell Press 30
During your opponent's next turn, this Pokémon takes 30 less damage from attacks (after applying Weakness and Resistance).

Weakness {Lightning} ×2

Retreat {Colorless}{Colorless}

Fusion Strike

{Water} Tongue Slap 10
{Water}{Colorless} Wave Splash 20

Weakness {Lightning} ×2

Retreat {Colorless}{Colorless}

Sword & Shield

{Water}{Colorless} Water Splash 20+
Flip a coin. If heads, this attack does 20 more damage.

Weakness {Lightning} ×2

Retreat {Colorless}

Sun & Moon

{Colorless} Tackle 10

Weakness {Grass} ×2

Retreat {Colorless}{Colorless}

Generations

{Water}{Colorless} Rain Splash 20

Weakness {Grass} ×2

Retreat {Colorless}

BREAKpoint

{Water} Razor Shell 10+
Flip a coin. If heads, this attack does 10 more damage.

Weakness {Grass} ×2

Retreat {Colorless}{Colorless}

{Water}{Colorless} Clamp 30
Flip a coin. If heads, your opponent's Active Pokémon is now Paralyzed. If tails, this attack does nothing.

Weakness {Grass} ×2

Retreat {Colorless}

Secret Wonders

{Colorless} Shell Rest
Remove 2 damage counters from Shellder.
{Water}{Colorless} Tongue Slap 20

Weakness {Lightning} +10

Retreat {Colorless}

Dragon Frontiers

{Fighting} Shell Grab 10
Flip a coin. If heads, the Defending Pokémon is now Paralyzed.

Weakness {Lightning} ×2

Retreat {Colorless}

Shellder δ

FireRed & LeafGreen

{Colorless} Minimize
During your opponent's next turn, any damage done to Shellder by attacks is reduced by 20 (after applying Weakness and Resistance).
{Water} Wave Splash 10

Weakness {Lightning} ×2

Retreat {Colorless}

Expedition Base Set

{Water} Irongrip 10
{Colorless}{Colorless} Lick 10
Flip a coin. If heads, the Defending Pokémon is now Paralyzed.

Weakness {Lightning} x2

Retreat {Colorless}

Gym Heroes

{Colorless} Tackle 10
{Water}{Colorless} Clamp
Flip a coin. If heads, the Defending Pokémon is now Paralyzed. If tails, this attack does nothing (not even damage).

Weakness {Lightning} x2

Retreat {Colorless}

Misty's Shellder

Fossil

{Water} Supersonic
Flip a coin. If heads, the Defending Pokémon is now Confused.
{Water} Hide in Shell
Flip a coin. If heads, prevent all damage done to Shellder during your opponent's next turn. (Any other effects of attacks still happen.)

Weakness {Lightning} ×2

Retreat {Colorless}