The Kracken

the Dark Spawn Kracken.

The Kraken is a mythical sea monster, summoned by Malefor to gain the atlantian spear. It took control over Vinny in order to kill the team from within, but it's control was brief cause of Mole hitting Vinny, and the Kracken was later blown up by Toothless' fireball. it was a dark spawn monster which was an agent of Malefor, sent by him to aid the villain leage after the Griffin stoled the spear and lost it.