The Mechanic is the head of a stolen car ring. Don't call him "thief." Already having developed a considerable criminal reputation on his own, he becomes even more dangerous when he steals tools from the Autobot Ratchet. It is debatable how much this additional power helped him deal with a deep-seated phobia of law enforcement officials.
Marvel Comics continuity
Nestor Forbes wasn't just a car thief, but the creator of a small criminal empire, calling himself "The Mechanic." During a transaction in which he was ambushed by the police, Forbes accidentally stumbled into the Autobot, Ratchet, while attempting to escape. Ratchet, eager to avoid capture himself, was forced to use a cryogenic sprayer and a laser scalpel as weapons against the pursuing police vehicles right in front of the stunned Forbes. Forbes immediately jumped on the opportunity, and removed Ratchet's tools to use for himself. He then attempted to invade the Ark in search of more alien technology, but was chased away by Prowl, whom Ratchet repaired just enough to seize upon Forbes' phobia of law enforcement. However, Forbes managed to get away with a power booster rod, in addition to the tools he had previously stolen from Ratchet.
Forbes soon resurfaced as the head of a substantially increased operation. In an attempt to retrieve the Autobots' stolen property, Grimlock ordered Blaster and Goldbug to locate The Mechanic. After Forbes proved more than a match for the pair of Autobots and the police put together (but working at cross-purposes), Blaster chose to defy Grimlock's orders regarding the humans and formed an alliance with them. Working together, the Autobots and the police were able to take down The Mechanic's entire operation, but Forbes himself was able to escape again with the power booster rod and Ratchet's medical equipment.
However, he was never seen nor heard from again.
- The Mechanic's real name is not revealed during his first appearance, but is used only in "Mechanical Difficulties!"
- Like Robot Master/Donny Finkleberg, Bob Budiansky based The Mechanic on a fellow employee, in this case a Marvel editor. However, it is unknown at this time just which editor The Mechanic was based on.