AttackFast-Acting Poison
Flip 2 coins. If both are heads, the Defending Pokémon is now Confused and Poisoned.

Gym Challenge is a set in the Gym series. It was released on 16 October 2000. The printed size is 132, and the checklist is the same length. Koga's Ekans is 77/132, in position 77 of 132 on this checklist. Before it is 76 Giovanni's Nidoran ♂, and after it is 78 Koga's Grimer. The listed rarity is Common.
Koga's Ekans is a Basic Grass Pokémon with 50 HP. The card lists level 17. In the Pokédex this is Ekans (#023), generation 1 (Kanto). The card lists Arbok, Arbok (#024) under evolves to.
Ken Sugimori illustrated this card. The same name is on 1,112 other cards in the catalog.
Ekans (#023) has 16 other cards in the catalog. Those other cards are in 15 sets. The other printings with a release date run from 1999 to 2025. The earliest other card is Ekans 46/62 in Fossil (1999). That card is named Ekans, while this one is Koga's Ekans. That card lists 40 HP, and this one lists 50 HP. Both list the rarity Common. Kagemaru Himeno illustrated that card, and Ken Sugimori illustrated this one. 12 other cards of Ekans list a different HP.
The attack Fast-Acting Poison lists 10 damage. The cost is Grass. Flip 2 coins. If both are heads, the Defending Pokémon is now Confused and Poisoned. Weakness is Psychic ×2. Retreat cost is 1.
I keep a set binder for Gym Challenge, meant to hold every card of that set. This card is one slot in the Gym Challenge set binder. A generation binder holds one card of each species. Ekans can fill a slot in Generation 1 binder (Kanto). Themed lists that include this exact card are Trainer's Pokémon and Kanto Gym Leaders and their Pokémon. I still need this card.
Flip 2 coins. If both are heads, the Defending Pokémon is now Confused and Poisoned.
Gym Challenge, in the Gym series. It was released on 16 October 2000. The printed size is 132.
77/132. It is entry 77 of 132 in this checklist.
Ken Sugimori. The catalog lists 1,112 other cards with that illustrator.
Common.
Ekans #023, generation 1 (Kanto).
Fast-Acting Poison (10).