Fang

Fang is a Decepticon from the Generation 1 continuity family

Fang is the one acting like a jerk.

Fang is a jerk, an asshole if you will. He likes to go into bars and beat up innocent Piano Transformer guys because they don't play the music he wants.

His alternate mode is unknown.

Comics

Events from the UK-only comic stories are in italics.

Fang entered Maccadam's Old Oil House in a bad mood. Annoyed that the piano was not playing the music he wanted, he demanded the poor bot call him "sir", then started beating the machine up with his pile driver hand and lasers from his foot. He beat the piano transformer up some more, than asked if anyone else wanted to take him on.

Twin Twist did. It didn't go too well for Fang after that point.

From Teletraan I: The Transformers Wiki, a Wikia wiki.