The Kraathatrogon are a species of gigantic worm-like creatures from Dimension X, who produce Mutagen and are vulnerable to salt...
The adult worms can reach the size of 100 feet long or more.
They have a weird simian face in the tip of their tails and two long antennas which the Kraang - and April - use to ride and control them.
The Kraang 'milk ' them for Mutagen as if they are cows.
One of the Kraathatrogon, that April and Casey were riding on, seemingly ate Tiger Claw and he is seemingly sent to the dimension of 1987.