King’s Rock

Held in battle : Holder's damaging moves have a 10% chance to make their target flinch. This chance applies independently to each hit of a multi-hit move. This item's chance is rolled independently of any other move effects; e.g., a move with a 30% chance to flinch normally will have a 37% total chance to flinch when used with this item, because 3% of the time, both effects activate. Held by poliwhirl or slowbro : Holder evolves into politoed or slowking, respectively, when traded.

“A hold item that may cause flinching when the foe is hit.”