Brains

Brains is a drone known as the "brain unit" created by Shockwave in order to download data but the unit decided to run away from the Decepticons. He is very smart that's what Wheelie, his best pal, thinks anyway.

Dark of the Moon film
Brains and Wheelie live in a apartment in Washington D.C. with Sam Witwicky and his new girlfriend, Carly. He is also refered to as being weird and creepy to Sam and Carly, Carly says she found him in her underwear drawer.

They enjoy watching the original Star Trek series together. When an episode is on the television, they comment that it is "the one where Spock loses it".

He helps Sam, Simmons and Dutch gather information on the rising situation. When Carly comes in, Bumblebee jumps and knocks down the chandler, Brains transforms and says, "That was smooth, Bumblebee!". He then proceeds to plug his "USB" hand into a printer to print out some crucial information he discovered. Brains and Wheelie join the battle in Chicago, by hijacking a Decepticon fighter and crashing it into the larger Decepticon carrier ship, although the latter part was unintentional, as they were caught within a tractor beam. During the time they were on the carrier, they dropped some of the Decepticon fighters on Soundwave and several other Decepticons, saving Bumblebee, Ratchet and Dino and allowing Bumblebee to kill Soundwave. Later they venture into the heart of the carrier and proceed to "screw the ship up". When they finish sabotaging the carrier, which is descending towards the ground quite fast, Wheelie says "We had a good run Brains, me and you." to which Brains replies "Yeah, but we're gonna die."

Dark of the Moon novel
Both Wheelie and Brains survive the crashing Decepticon ship, and swim away from the wreckage.