An anomaly. His DNA contained too much canine DNA, and he was imprisoned with the other anomalies in the subterrainian area of Manticore. He helped Max escape, and later escaped himself, along with the other anomalies, in "Designate This." He live in the house formerly occupied by "Sandman" (see "Designate This" and "Proof of Purchase") up until "She Ain't Heavy".

His double was Isaac, one of the first 2 prototypes made by the "father" (Sandman) at Manticore, and when the father left, Isaac couldn't stop crying. To silence him, the soldiers beat him and eventually cut his tongue off. In "Two," Joshua was blamed for the murders of several sector cops, but it was really Isaac. Joshua didn't blame him for being a killer, but had to stop him when Isaac attacked Max.

Joshua also enjoys painting, and found out partly by accident. An art critic named Meena told him that even though he could never be accepted in society, he should still paint to express his own creativity ("Medium Is The Message"). Joshua also fell in love with a blind woman named Annie, but she was killed by White in an attempt to frame Joshua and bring transgenic paranoia to a head ("Dawg Day Afternoon"). This made Joshua want to be with his own kind, and he moved to Terminal City (She Ain't Heavy").