A Stink Sack is an explosive sea-like object. It only comes out when you're chopping a Twelve Legged Cave Frog in a machine. First, the Sack fogs green stink, and then glows when ready. Stink Sacks taste horrible, and Chowder once threw one onto Shnitzel, and then it exploded.
The Stink Sack
Chowder holding a stink sac