Trailbreaker

Trailbreaker makes light of any situation, no matter how serious. Practical joker and cheerleader, but considers himself a liability to Autobots since he consumes the most fuel. Lacks self-esteem and often asks to be left behind. Projects nearly impenetrable invisible force-field. Can jam radio transmissions. Very slow. Often mopes about his handicaps, but his bravery and defensive prowess is unquestioned.

(Source: Wikipedia)