Doc

The Doc is a doctor (obviously) who was medically helping Jeff and Donut even when they were kids. Currently he resides in Canada.

Season 2
Fifteen years in the past, Jeff, as a kid, pays a visit to the Doc for some pills he needs. The Doc tells him to only take two a day, and Jeff agrees to the condition, but later abuses them anyway. He starts to hallucinate and sees the Doc telling him about how many pills he should take again. Once again in the past, and once again approximately fifteen years in the past, after Donut and Rob get into an accident with a truck, they are brought to the hospital. The Doc is able to replace Donut's damaged head with a giant donut, but is not able to save Rob's face.

Season 3
Back in the past, Jeff leaves the Doc after getting his pills, and spots Donut. In the present, when Donut wakes up in a hospital in Canada after coming back to life, he is greeted by the Doc. The Doc explains that he moved to Canada and the two are surprised to see each other.

Later, Donut decides to see if the Doc would be willing to join him and his team. However, when Donut and co. arrive at the hospital, they find it to be completely destroyed. Inside is wall to wall blood, and the Doc's glasses laying in a puddle of it, without a body in sight. Donut realizes that it was probably Jeff to returned to get more pills, and must have killed the Doc in the process.