Patrick "Old" McNinja was a clone of Dr. McNinja who was created in 1990 due to Dr. McNinja's frustration with college, as he was unable to learn everything he wanted to in the lifespan he had. Benjamin Franklin cloned the soon-to-be Dr. McNinja umpteen times. Each clone was given a different field to study and become an expert at and return 8 years later. Every clone made it except for the clone whose expertise was agriculture (farming). He saw the lab where the clones and the original were to be fused was exploded and left. He turned to a life of farming and named himself Old McNinja. He was captured by Knickerbockers and Mongo and was used as bait for the McNinja family in Army of One. He later decided to work for King Radical, though after having infiltrated the McNinja household claimed not to be Radical's spy and was actually just seeking a chance to be himself again.
Old believed that he had began breaking apart, as he believed that the technology used to make him was old and the clones it made were not meant to last as long as he had. Driven into a breakdown while speaking with his family, he tried to escape while his parents attempting to convince him to stay and talk. Before escaping with a smoke bomb, he revealed his perceived sickness and how his life was messed up after his progenitor ejected him from it, lamenting that his girlfriend didn't want him anymore and that he couldn't speak with his own family without breaking down. He later joined forces with King Radical and fought his clone in the new government building, though he as eventually convinced that he was not degrading - as Benjamin Franklin used the very same technology as him and lived to a ripe old age before being murdered. His original offered him psychological help after they'd get out of there, and the two teamed up to find Gordito, who had been captured by Dracula earlier. However, the McNinja parents betrayed them, as Gordito had been turned into a vampire and Dracula's sole condition to release him was for Mitzi and Dan to lure the two into a portal that would take them far away from the pyramid, where King Dracula and his forces awaited to kill them.
The two fought dozens of Radical's goons, killing many with their swords and stolen guns. Ultimately, Old was stabbed through the back with a chainsaw by King Radical, who dropped him onto his original. With a last laugh, he died in Doctor McNinja's arms. He later met Benjamin Franklin in Purgatory.
Having been cloned prior to his original breaking up with Hortense, he still had a crush on her despite her not returning the feelings due to what happened between her and the doctor.
- Dan McNinja - Father
- Mitzi McNinja - Mother
- Patrick McNinja - Original
- Sean "Dark Smoke Puncher" McNinja - Brother
- John McNinja - Grandfather, deceased
- King Radical - Former superior and killer, deceased
- Franz Rayner - Former kidnapper and former ally, deceased
- Dracula - Former ally, deceased
- Donald McBonald - Former ally
- Mongo - Kidnapper
- Dr. Knickerbockers - Kidnapper; used him as a clone template