AttackBerserker Splash
This attack does 10 damage to each Benched Pokémon (both yours and your opponent's). (Don't apply Weakness and Resistance for Benched Pokémon.)

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 20/98 in Ancient Origins, position 20 of 101. Before it is 19 Magikarp, and after it is 21 Gyarados. The set belongs to the XY series. It was released on 12 August 2015. The printed size is 98. This checklist is longer, at 101 cards. The listed rarity is Rare.
The attack Berserker Splash lists 80 damage. The cost is Water, Colorless, Colorless. This attack does 10 damage to each Benched Pokémon (both yours and your opponent's). (Don't apply Weakness and Resistance for Benched Pokémon.) Aqua Tail is another attack lists 90+ damage. The cost is Water, Colorless, Colorless, Colorless. Flip a coin for each Water Energy attached to this Pokémon. This attack does 30 more damage for each heads. Weakness is Lightning ×2. Retreat cost is 3. The flavor text reads "Rarely seen in the wild. Huge and vicious, it is capable of destroying entire cities in a rage."
Gyarados (#130) has 56 other cards in the catalog. Those other cards are in 39 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. The rarity there is Rare Holo, and here it is Rare. Mitsuhiro Arita illustrated that card, and Shin Nagasawa illustrated this one. 43 other cards of Gyarados list a different HP.
The illustrator line reads Shin Nagasawa. I count 303 other cards in the catalog with that illustrator.
Ancient Origins set binder is where a full Ancient Origins 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.
This attack does 10 damage to each Benched Pokémon (both yours and your opponent's). (Don't apply Weakness and Resistance for Benched Pokémon.)
Flip a coin for each Water Energy attached to this Pokémon. This attack does 30 more damage for each heads.
Rarely seen in the wild. Huge and vicious, it is capable of destroying entire cities in a rage.
Ancient Origins, in the XY series. It was released on 12 August 2015. The printed size is 98.
20/98. It is entry 20 of 101 in this checklist.
Shin Nagasawa. The catalog lists 303 other cards with that illustrator.
Rare.
Gyarados #130, generation 1 (Kanto).
Berserker Splash (80) and Aqua Tail (90+).