Kerokero (ケロケロ) is an enemy Badnik that appears in Sonic Advance.
The KeroKero is a pink robotic frog enemy found in Neo Green Hill Zone. They make small jumps towards the player, and they can be seen croaking occasionally. They are only dangerous if the player runs into one accidentally. Any form of attack, particularly a Spin Attack or Spin Dash, will destroy them.
Kerokero's name is derived from "Kero", a Japanese onomatopoeia for the croaking of a frog.