Qwilfish

The opponent has a 30% chance of being induced with Poison when using an attack, that requires physical contact, against this Pokémon.

When rainy, The Pokémon’s Speed doubles.

Upon entering battle or receiving the ability, the opponent’s Attack lowers one stage. In a Double Battle, both opponents’ Attack are lowered. Pokémon with the Clear Body, Hyper Cutter, or White Smoke ability are unaffected. In a link battle, if both sides switch on the same turn, and first player sends out a Pokémon with Intimidate, the opponent’s Attack will be lowered before the opponent’s Pokémon switches.