sentinel prime

Sentinel Prime is a member of Cybertron's Elite Guard under the command of Ultra Magnus. Sentinel has a history of rivalry with Optimus Prime, who attended the Autobot Academy with him. Back in their academy days, he was something of a maverick, leading the more responsible Optimus to refer to him as a "walking dysfunction." Of course, he's the one who ended up in the Elite Guard while Optimus was sent to repair space bridges, a fact he loves to remind his former classmate of... even though it was only because of Optimus that he got the position. He also has a bit of a superiority complex towards non-Guard Autobots, not to mention being intensely organic-phobic.
He usually transforms into a Cybertronic bulldozer, but temporarily took the form of a snowplow truck during his time on Earth. He later returned to his original form after leaving the planet. He possesses an energy lance and an arm-mounted shield that can expand into a force field, as well as be thrown as a weapon. He'd basically be a knight in shining armor, if he had a better personality.
However, despite his arrogant exterior, there is a spark of kindness in him. He genuinely cares for his friends and on extremely rare occasions, he shows a small degree of respect for Optimus. But more often than not, Sentinel has a lot of trouble showing his concern for his friends and his begrudging respect for Optimus.

Don't mention his chin. He's a little touchy about it.

In this alternate universe of Transformers Animated, where the Decepticons won by strategy and necessary information extracted from Shockwave's spy Cybertron data.
In this alternate universe 50% of the Autobots are captured and sent to auction or clandestine kennels to be trained to be Decepticon pets. Autobots have no basic rights in this universe. Another 50% of the Autobots were brainwashed to fit into the new Decepticon society on Cybertron.