|“||I've murdered a dozen women, terrorized the city. What have you done? Chopped up your mommy?||„|
|~ Greenwood to Jerome Valeska|
|“||There's nothing more contagious than laughter!||„|
|~ Greenwood's last words, stealing Valeska's line|
In the series
After killing young women and eating his victims he was caught and sent to Arkham Asylum.
When Zaardon is brought in Greenwood and the other inmates do not care about him until Zaardon dies and erupts in a cloud of knock out gas which narcotizes the inmates, including Greenwood. He and five other inmates are then busted out by Tabitha Galavan and brought before her brother Theo who invited them into his team, revealing that each of them has their own set of skills. When Richard Sionis denies his offer, Galavan has him killed by his sister. The other psychopaths then all accept Galavans offer. The group then refer to themselves as the Maniax.
While briefing the police department about the missing inmates, Gordon reveals that Greenwood murdered and ate a dozen women.
As a member of the Maniax, Robert alongside Jerome, Dobkins and Helzinger kidnaps seven workers from a shipyard and then throws them off a roof.
Later at their headquarter the Maniax are visited by Theo Galavan. He tells them that they will be on TV soon.
Rivalry with Jerome
While in their new headquarter Jerome finds a sword which Greenwood immediately takes from him. When Jerome asks him nicely to give it back, Greenwood tells Jerome to "make him", calling him a little brat. Jerome takes a chainsaw and the two of them prepare to fight but are interrupted by Theo Galavan. When Dobkins chides them because they are a team, Greenwood proclaims himself the team captain but is denied by Jerome. Sensing the tension between the two, Galavan states that this problem must be resolved immediately. He draws his gun and removes all but one bullet, asking them if they know this game (Russian Roulette). Greenwood takes the gun, aims at his head and shoots but nothing happens. When Jerome does this not once but three times Jerome is made the boss of their organization with Galavans permission.
Greenwood and the Maniax next board a cheerleader bus which they plan to blow up with the gas from the refueling truck. Their plan is foiled by Gordon. Greenwood is one of the Maniax who is able to escape but Arnold Dobkins is caught.
After Barbara lures Gordon out of the GCPD, the Maniax enter the building disguised as policemen and shoot up the precinct. While his colleagues die in the precinct, Gordon is attacked and beaten by Helzinger. When the Maniax shoot up the police precinct, Robert Greenwood finds Dobkins body. He laughs at the fate of his former colleague and leaves the room. He later films Jerome while he threatens Commissioner Essen. When he steals a line from Jerome, Jerome shoots him in the chest, killing the cannibal.