The Red Death

The Red Death is the main antagonist of How To Train Your Dragon. He kills to get whatever he wants, so he's an evil bully.

Role in How to Train Your Dragon
His first appearence was when he ate a Gronckle. The vikings sent the other dragons fleeing, but they didn't know somebody evil was inside. Hiccup and Toothless took him on. Toothless killed him by setting his mouth on fire and sending him crashing into the island.