AttackDragon Spark
This attack does 10 damage to each of your opponent's Pokémon. (Don't apply Weakness and Resistance for Benched Pokémon.)

Deoxys is a set in the EX series. It was released on February 1, 2005. The printed size is 107. This checklist is longer, at 108 cards. Gyarados is 8/107, in position 8 of 108 on this checklist. Before it is 7 Dusclops, and after it is 9 Jirachi. The listed rarity is Rare Holo.
Gyarados is a Stage 1 Water Pokémon with 90 HP. In the Pokédex this is Gyarados (#130), generation 1 (Kanto). The card says it evolves from Magikarp. In this catalog that name is Magikarp (#129).
Hisao Nakamura illustrated this card. The same name is on 71 other cards in the catalog.
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 90 HP. Both list the rarity Rare Holo. Mitsuhiro Arita illustrated that card, and Hisao Nakamura illustrated this one. Retreat cost there is 3, and here it is 2. 52 other cards of Gyarados list a different HP.
The attack Dragon Spark lists no damage number. The cost is Water. This attack does 10 damage to each of your opponent's Pokémon. (Don't apply Weakness and Resistance for Benched Pokémon.) Full Retaliation is another attack lists 20× damage. The cost is Colorless, Colorless. Does 20 damage times the number of damage counters on all of your Magikarp. Pulverize is another attack lists 50+ damage. The cost is Water, Water, Colorless, Colorless. If the Defending Pokémon already has at least 2 damage counters on it, this attack does 50 damage plus 50 more damage. Weakness is Lightning ×2. Retreat cost is 2.
I keep a set binder for Deoxys, meant to hold every card of that set. This card is one slot in the Deoxys set binder. A generation binder holds one card of each species. Gyarados can fill a slot in Generation 1 binder (Kanto). I still need this card.
This attack does 10 damage to each of your opponent's Pokémon. (Don't apply Weakness and Resistance for Benched Pokémon.)
Does 20 damage times the number of damage counters on all of your Magikarp.
If the Defending Pokémon already has at least 2 damage counters on it, this attack does 50 damage plus 50 more damage.
Deoxys, in the EX series. It was released on February 1, 2005. The printed size is 107.
8/107. It is entry 8 of 108 in this checklist.
Hisao Nakamura. The catalog lists 71 other cards with that illustrator.
Rare Holo.
Gyarados #130, generation 1 (Kanto).
Dragon Spark, Full Retaliation (20×), and Pulverize (50+).