Butt and Head

Butt and Head are the Terrible Terrors that Ruffnut and Tuffnut trained in the episode Worst in Show. They are considered to be the second dragons that Ruffnut Thorston and Tuffnut Thorston have officially trained in the series.

Appearance
Butt and Head are both yellow, with orange highlights. Both are the size of a typical Terror. In Rise of Berk, Head seems to have a slightly more green tint to its tail, wings, and horns.

Behavior
Much like their trainers, Butt and Head appear to be slightly dimwitted as their only apparent skill is headbutting people or each other. They also appear to have an inner prankster, which was demonstrated when tackling Mildew in the head at the same time, from opposite sides.

Skill
They have learned from the Twins to head butt one another. Aside from this, they have no shown no sign of other unique abilities or skills.

Headbutting: Ruffnut and Tuffnut trained the two Terrors a skill to fly into each other. They used this tactic to knock out Mildew on the Outcast ship while they were trying to get Meatlug back. This idea was thought by their headbutting when agreeing.