Mr. Nobody was first introduced in 1964, then again in 1989. He was in one issue of the original Doom Patrol series as a member of the Brotherhood of Evil. He stole Rog, a robot designed by the Chief for lunar exploration.
To explain his absence in the DCU, Grant Morrison wrote a story to explain that Monsieur Mallah and the Brain threatened to kill him if they ever saw him again, so he hid in Paraguay for a long time. He came back into society to undergo experiments by Dr. Bruckner, an ex-nazi scientist that would eventually grant him the ability to drive people insane by draining their sanity. Unfortunately, he was driven insane himself by the experimentation, becoming a living shade, who thought of himself as "the spirit of the twenty-first century", who considered the universe, to quote him verbatim, "a drooling idiot with no fashion sense". He created the Brotherhood of Dada, a form of the Brotherhood of Evil that shared his demented ideals, recruiting Sleepwalk, who has strength when sleepwalking, Frenzy, a Jamaican illiterate man who can transform into a cyclone, Fog, who can absorb humans into his being when he is in his gaseous form, and the Quiz, a Japanese woman who has every superpower nobody has ever thought of. Together, the brotherhood steals a psychoactive painting and uses it to absorb Paris, France and some members of the Doom Patrol. The Brotherhood of Dada help the Doom Patrol stop the Fifth Horseman. Afterwards, they decide to stay in the painting, finding it an ideal world for them. Mr. Nobody does not want to stay in the painting, but is stuck there anyway.
Mr. Nobody escapes the painting with the help of the members of a second Brotherhood, the New New New Brotherhood of Dada. He tried to run for president by powering his campaign with the lysergic resonance of Albert Hoffman's bicycle, but the US Government wouldn't allow him to reach office. Instead, they sent their similarly bizarre agent John Dandy after him. Dandy killed almost every member of the second Brotherhood, including Mr. Nobody; one of John Dandy's six floating faces was shoved into his head, cutting him from his powers. He was impaled on a broken pole and was assumed dead for an extended period.
However, much later, Enigma revealed Mister Nobody did indeed survive, but was very rarely seen after his apparent death. He was considered as a candidate to receive the power of the Dark Arcana's Fool card and later participated in the Final Battle for the Arcana in Metropolis.
After the Doom Patrol relocate to Oolong Island, he somehow takes possession of former Doom Patrol bank roller Thayer Jost and set about creating a new corporate backed team of heroes, called the Front Men. The Front Men consist of vintage Doom Patrol villain Animal-Vegetable-Mineral Man, as well as two new villains, Botfly and Porcelain Doll, following the public's shifting opinion of heroes following the Blackest Night. He lured the Doom Patrol into a trap where he had them fight the Front Men in front of various reporters, giving the impression that they had been attacked without provocation. His plan seems to be to control the populace through the media by swaying their opinions.
He also murdered the former Brotherhood of Dada member called the Toy, apparently to kill any connection to his past.
Mr. Nobody has somehow been transformed into Mr. Somebody. Whereas Mr. Nobody embodied anarchy and Dadaism, Mr. Somebody embodies late stage capitalism. How he transformed is yet to be explained, as is how he came to possess Jost.