Hobblegrunt

The Hobblegrunt is a new dragon species that made its debut in the movie, How to Train Your Dragon 2.

Dragon Appearance
The Hobblegrunt has a single horn and and an expandable frill surrounding its head. It has clawed wings, small arms and big legs like a Deadly Nadder. It also appears to have long neck and tail as well. The Hobblegrunt doesn't have a particular colour, but instead it changes color depending on its mood:
 * Yellow: Happy
 * Purple: Curious
 * Red: Angry

Notable Abilities

 * The Hobblegrunt is able to change its colors like a chameleon, and this ability is similar to that of the Changewing. Instead of doing it for defensive purposes, it changes colour depending on its mood. It can use this ability to calm other dragons.
 * Its fire type is an ethane expectorant.
 * Using the large frill on its head, the Hobblegrunt is able to sense its surroundings.

Trivia

 * Valka owns a small Hobblegrunt named Gruff that was blinded by a tree snare trap.
 * The Hobblegrunt is the second dinosaur-like dragon, with the first being the Speed Stinger. It is also the second dragon that is able to change its colors, with the first being the Changewing.
 * Although the 'Guide to the Dragons' stated that the Hobblegrunt was a Boulder Class dragon, the official website later revealed it was a Stoker Class dragon.
 * The Hobblegrunt is officially in School of Dragons for a limited time. However, they look more like another, currently unknown, species of dragon that appeared in the sequel.
 * The Hobblegrunt is similar to Mood-Dragon in the books.
 * According to the Fishlegs' Dragon Stats, Hobblegrunts are, during the time of How to Train Your Dragon 2, the newest addition to the Stoker class.