Insomniain Pokémon Polished Crystal

Insomnia is an ability that prevents the user from falling asleep. This can be particularly useful against opponents that use sleep-inducing moves like Sleep Powder or Hypnosis! Drowzee is a notable Pokémon that has this ability in Polished Crystal, but it is also found on several other Pokémon as well, including Delibird and Mewtwo.