Theo Possible

Theo Possible was a time travelling adventurer and DJ. He was a black man of indeterminable age who dressed entirely in white. He had braided silvery hair and a goatee. Theo's white suits were made by S. Stratton. (PROSE: Party Kill Accelerator!) He wasn't human. (PROSE: Happily Ever After Is a High-Risk Strategy)

History
Theo trained with the Venusians to become an Ascended Master of Klatch-Ki. (PROSE: Party Kill Accelerator!)

While having adventures in time and space, Theo had numerous encounters with Obsèque Bleak which ended when Theo killed Bleak. Theo travelled with Steve for some time, but that ended when Steve was disintegrated by an Asymmetry Fiend.

Theo eventually semi-retired from the adventuring life. (PROSE: Happily Ever After Is a High-Risk Strategy)

Theo hosted a party in the Zona Obscura for all the ideas which had become "lost in the ether". Theo was the festival's DJ; as a "sort of cultural exchange" Kelsey from Faction Paradox held his records. For a while, Theo gave the ideas an eternal celebration, but it all came to a stop when Jimmy the Mandrill invited Iris Wildthyme and Panda and their presence instigated a narrative. Theo had to work with Iris to try to stop Jimmy from consuming all the guests at the party. Kelsey finally killed Jimmy, but some of the DJ equipment was damaged in the process, meaning the party could not continue. Theo left the Zona Obscura in a London Underground train after giving Kelsey his record box. (PROSE: Party Kill Accelerator!)

Theo DJed at the after party for the coronation of Salvinder Heat-Death in the City of the Saved.

On another occasion, Theo was invited to the City of the Saved by his old companion Steve to attend Steve's engagement party in the Achaean District. Steve had invited Theo because the woman to whom he was engaged was Helénē of Troy and they needed help getting away from all the Greeks and Trojans that also wanted Helénē. Theo helped Steve and Helénē escape in a U-boat and he was left with a pedalo as his escape vehicle. Theo pedalled for his life and managed to escape to a major road in the nick of time.

Theo hitchhiked in Cranzfraction and rested for the first portion of the journey back to the Uptime Gate. Theo woke up while Cranzfraction was telling his life story to Terrence Moody and recognised the name "Litany Chromehurst", but couldn't place it. Theo then told Cranzfraction and Terrence the story of his recent adventure with Steve and Helénē. After arriving at the Uptime Gate, Theo treated Terrence to a meal at Lucrezia's Diner. Theo introduced Helénē to Terrence, (PROSE: Happily Ever After Is a High-Risk Strategy) instigating a relationship which would result in the two marrying. (PROSE: Apocalypse Day)

Behind the scenes
Theo Possible appeared in the Señor 105 novella By the Time I Get to Venus, which also features Señor 105, El Jefe, Litany Chromehurst, and the Venusians from the First Doctor novel Venusian Lullaby. This story was later reprinted in The Rise and Fall of Señor 105.

Blair Bidmead, the creator of Theo Possible, made a webcomic for the character called Entirely Possible. He also wrote a Christmas-themed short story called Grumpy Auld Men where Possible met the Twelfth Doctor.

Theo also appears in Bidmead's short story Significant Others from the Obverse Books charity anthology . The story features Rose Tyler travelling with Possible after the events of Journey's End.