Biography: The Doom Patrol consists of its leader, Mento, Elastigirl, Negative Man, Robot Man and, at one time, Beast Boy.
When Beast Boy disobeyed Mento’s orders to take down the Brotherhood of Evil before saving the rest of the Doom Patrol, a rift between the two formed. It’s not clear exactly when or what the reason for Beast Boy’s leaving was, but it seems that that rift has yet to be repaired.
Beast Boy was sent a distress signal from Mento; after receiving it, Beast Boy went to rescue his old teammates. In the process, he, again, let the Brotherhood of Evil escape in favor of saving both the Doom Patrol and the Teen Titans.
After defeating the Brain and his second Quantum Generators, the Doom Patrol returned back to their headquarters. After becoming friends with the Titans, they parted ways with them and Garfield (that's Beast Boy to all of you).
Mento The leader of the group, Mento is able to read minds and send out a kind of “brain wave” that will destroy things upon contact.
Elastigirl Able to become gigantic at will, Elastigirl considered to be “second” in command.
Negative Man While not the most powerful of the group, Negative Man is able to separate himself from his body and become an ethereal being to infiltrate and destroy machines.
Robot Man A super powerful and almost invulnerable robot with the only human part being a brain; he’s what Cyborg considers an “early prototype” of himself.
Beast Boy Once the youngest member of the group, Beast Boy was the shape shifter who eventually left and joined the Teen Titans.