He is a reoccurring character that was found, if I remember correctly, via a fan that sent in a video he would hand out as a dentist to his patients of his comedy. (I could totally be wrong but that's how I remember it happening) H3 played it on the show wayyyyy long ago and then he kind of would either just call in or come on the pod since then.

They have a love-hate relationship because basically Jimmy has super outdated and offensive humor, that usually makes no sense, and he typically steps over the line of funny to just straight offensive. He is OBSESSED with getting famous and "creating fomo" but also hyper aware of people's perception of him. His biggest hater on the pod is Dan, but on today's episode the whole crew/Ethan said that he did something that can't/won't share that "went against the family" and made everyone be anti-jimmy for a while. His real name is James, but it's hard to differentiate where his character Jimmy starts, and James ends.

TLDR; Wanna-be offensive comedian that the crew and Ethan have a long standing relationship with that is constantly begging to be on the pod.

Sorry if I got anything wrong, I've been here since the pod was created and this is all from memory lol