AttackThrash Tackle
Gyarados does 20 damage to itself.

Gyarados is Pokédex #130, generation 1 (Kanto). Gyarados is a Stage 1 Water Pokémon with 130 HP. The card says it evolves from Magikarp. In this catalog that name is Magikarp (#129).
Gyarados sits at 6/16 in Pokémon Rumble, position 6 of 16. Before it is 5 Starmie, and after it is 7 Pikachu. The set belongs to the Other series. It was released on December 2, 2009. The printed size is 16, and the checklist is the same length.
The attack Thrash Tackle lists 80 damage. The cost is Water, Colorless, Colorless, Colorless. Gyarados does 20 damage to itself. Weakness is Lightning ×2. Resistance is Fighting -20. Retreat cost is 3.
Gyarados (#130) has 56 other cards in the catalog. Those other cards are in 38 sets. The other printings with a release date run from 1999 to 2025. The earliest other card is Gyarados 6/102 in Base (1999). That card lists 100 HP, and this one lists 130 HP. Mitsuhiro Arita illustrated that card, and Pokemon Rumble illustrated this one. 43 other cards of Gyarados list a different HP.
The illustrator line reads Pokemon Rumble. I count 15 other cards in the catalog with that illustrator.
Pokémon Rumble set binder is where a full Pokémon Rumble set goes. This card fills one slot there. A generation binder holds one card of each species. Gyarados can fill a slot in Generation 1 binder (Kanto). Themed lists that include this exact card are Magikarp and Gyarados. I still need this card.
Gyarados does 20 damage to itself.
Pokémon Rumble, in the Other series. It was released on December 2, 2009. The printed size is 16.
6/16. It is entry 6 of 16 in this checklist.
Pokemon Rumble. The catalog lists 15 other cards with that illustrator.
Gyarados #130, generation 1 (Kanto).
Thrash Tackle (80).