AttackWriggle
Flip a coin for each of your opponent's Pokémon. If that coin flip is heads, this attack does 30 damage to that Pokémon. (Don't apply Weakness and Resistance for Benched Pokémon.)

Gyarados is Pokédex #130, generation 1 (Kanto). Gyarados G is a Basic SP Water Pokémon with 110 HP. The card lists level 46.
Gyarados G sits at 30/127 in Platinum, position 30 of 133. Before it is 29 Golduck, and after it is 31 Infernape. The set belongs to the Platinum series. It was released on 11 February 2009. The printed size is 127. This checklist is longer, at 133 cards. The listed rarity is Rare.
The attack Wriggle lists no damage number. The cost is Water, Colorless, Colorless. Flip a coin for each of your opponent's Pokémon. If that coin flip is heads, this attack does 30 damage to that Pokémon. (Don't apply Weakness and Resistance for Benched Pokémon.) Dwindling Wave is another attack lists 100- damage. The cost is Water, Water, Colorless, Colorless. Does 100 damage minus 10 damage for each damage counter on Gyarados G. Weakness is Lightning ×2. 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 is named Gyarados, while this one is Gyarados G. That card lists 100 HP, and this one lists 110 HP. The rarity there is Rare Holo, and here it is Rare. Mitsuhiro Arita illustrated that card, and Kent Kanetsuna illustrated this one. 56 other cards of Gyarados list a different HP.
The illustrator line reads Kent Kanetsuna. I count 74 other cards in the catalog with that illustrator.
Platinum set binder is where a full Platinum 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.
Flip a coin for each of your opponent's Pokémon. If that coin flip is heads, this attack does 30 damage to that Pokémon. (Don't apply Weakness and Resistance for Benched Pokémon.)
Does 100 damage minus 10 damage for each damage counter on Gyarados G.
Platinum, in the Platinum series. It was released on 11 February 2009. The printed size is 127.
30/127. It is entry 30 of 133 in this checklist.
Kent Kanetsuna. The catalog lists 74 other cards with that illustrator.
Rare.
Gyarados #130, generation 1 (Kanto).
Wriggle and Dwindling Wave (100-).