Other known variants
+20-20Hidden Poison
If Haunter is your Active Pokémon and is damaged by an opponent's attack (even if Haunter is Knocked Out), the Attacking Pokémon is now Poisoned.
Tongue SpringChoose 1 of your opponent's Pokémon. This attack does 20 damage to that Pokémon. (Don't apply Weakness and Resistance for Benched Pokémon.)
It likes to lurk in the dark and tap shoulders with a gaseous hand. Its touch causes endless shuddering.
Roserade is receiving errata for its Poke-BODY, "Hidden Poison". Hidden Poison affects your opponent's Attacking Pokemon, not your Defending Pokemon. The correct card text should read, "If Roserade is your Active Pokemon and is damaged by an opponent's attack (even if Roserade is Knocked Out), the Attacking Pokemon is now Poisoned."