Grenukers has a green shell-like armor on its head and backside, with brownish skin. It is a slug that looks similar to a Hop Rock, but explodes after a while.They look like a grenade. Grenuker slugs live in Quiet Lawn Cavern. Its tronsformed apperance(if it has one) has not been seen on the show. Grenukers sleep for long periods of time on the ceilings of caverns but will awaken and fall if they hear loud noises or other disturbances.