Randomly attacks while asleep.
Sleep Talk is a Normal-type status move that allows the user to use one of its other moves at random while it is asleep. In Polished Crystal, Sleep Talk can be learned by various Normal-type Pokémon, providing them with a strategic option to continue attacking or supporting their team even while incapacitated by sleep.
This is a Move Tutor move. TThe location page may have more information on how to obtain it.