Mega Chompies[1] are silver, red armor wearing Chompies that have the ability to grow into a giant Chompy and spawn regular Chompies. In 3DS version of Trap Team, one Mega Chompy, Big Bertha Bubblethorn, is trappable.
Mega Chompies share similar appearances with the Chompy Mage's monster form.
The Running Mega Chompy in Skylanders SuperChargers Racing is nude like most Chompies, but in its icon seen above the health bar it's got a T-Shirt, like another Mega Chompies seen in the game.
In 3DS version of Trap Team, they are white and pink called Mutant Uber Chompies.
This make them the only Chompies in this game to have his name changed.
References
↑Skylanders: Trap Team Bradygames Strategy Guide, page 148