Scrub Sub

A substitute teacher who is gullible and half the time has no idea of what is going on around him/her.

--A class come into room and realizes they have a substitute teacher--

(Scrub Sub) "Do you have assigned seats?"
(Class) "No"
(That one annoying nerd that's always there) "Yes we do!"
(Scrub Sub) "I ain't no scrub sub!"