"AH! My back!"
Gideon Gibbus, more commonly known as Fatman, was a member of Professor's Gang.
At some point before the events of the third season. Fatman befriended the Professor and joined his gang.
Fatman met with the other gang members in the scrapyards for their introduction to the assassin. Although the meeting was interupted by General Phoenix, Fatman escaped and survivied. A while after this, Fatman was assigned to work with Wirez, Spike and Metalchest to hijack BoCo's train. After not using a silencer, he was shunned by Spike and mainly ignored by the group. Later, Fatman inspected a gantry crane Wirez was using, and fell off of it, braking his back, when it started. Fatman wasn't able to get up due to all the pain, and was run over by Stepney moments later.
Fatman was very gruff, and didn't think before he acted, as shown when he carelessly climbed onto the gantry crane and forgot to use a silencer. He was also doubtful and self-centered when his size was brought up. "I'm not fat, I'm...overweight!"
- Fatman's name is a parody of Batman. His real name, Gideon Gibbus, is a reference to the Fat Controller's French name from Thomas and Friends.
- Fatman bears a striking resemblence to the CEO of M.C. Bunn from Maiden Voyage.