• English / United States: Butch and Cassidy's Drowzee
• Japanese / Japan: コサブロウ&ヤマトのスリープ
• Japanese (Romanized) / Japan: Kosaburō & Yamato no Sleep
• Japanese (TL) / Japan: Kosaburo & Yamato's Sleep

Butch and Cassidy attached Drowzee to a device that would amplify Drowzee's hypnotic waves and broadcasts it through a parabolic antenna on the roof of their base. Drowzee would then use the attack to round up Pokémon by telling them to come to Butch and Cassidy's base on Mandarin Island. Drowzee could also command the controlled Pokémon to attack, regardless if it was their owner that they were attacking.

It's control over the Pokémon was stopped when Ash's Pikachu's Thunderbolt destroyed the control device. After Misty's Togepi's Metronome destroyed Butch and Cassidy's base, Drowzee has not been seen since.