He was voiced by Peter Cullen, best known for voicing Optimus Prime.
Despite his appearance and initially destructive nature, he is a creature with a sense of justice and is very friendly towards the ponies.
He, alongside with his four subordinates were tracking down some escape criminals known as "the Flories", tearing apart Dream Valley in their quest.
The Flories, making themselves out to be the victims, lied to Megan and the ponies, making them defeat and imprison the Crabnasties in a stone prison away from Paradise Estate.
After they realized that the Crabnasties were not the true threat, they helped them capture the Flories. One of the ponies, Posey, the first to call them out as evil monsters, apologized for their wrongful arrest and the Crabnasties responded by plowing her garden which they had accidentally destroyed.