- Originally, the Janitor was supposed to be a figment of J.D.'s imagination. The cast and crew were so sure that the series would be cancelled by the end of the first season that they kept it as their ace for their force series finale's plot twist. This idea was kept up through part of the second season until Neil Flynn asked to be able to interact with other actors other than Zach Braff.
- The majority of Janitor's lines are completely improvised by Neil Flynn. There's a joke among the writers of the show that Flynn has never spoken a line from the script.
[To JD] "You look unhappy. I like that."
"I don't jump out and scare you. I follow you around all day. I only got about an hour and a half of work around here, and the rest of the time I track you, like an animal."
Janitor: "You're stupid."
JD: "That's it?"
Janitor: "Give it time, it'll eat at ya."