The Good Omens Official Fanfiction Summer School (GOOFSS) is an OFU with a six-week term, staffed by characters from the novel Good Omens. It was originally written by Miss Morrigan and Miss Kali, but Miss Morrigan encountered unexpected RL troubles a few episodes in and left the chronicling to Miss Kali, which explains the long hiatuses between episodes, although she promises that the next one will be up soon.
GOOFSS is notable in that there are at least four PPC agents openly enrolled as themselves. At the moment they are being utilised as an impromptu police force by the Misses, since the Headmasters have disappeared, the students are writing unauthorised fics, and Chaos is reigning.
The minis of GOOFSS are mini-Hellhounds, or mini-Hellpuppies in the instances of Inappropriate Nicknames, which Aziraphale suffers from in particular. They are small, black, red-eyed hounds, which are adorable but bite. Do not taunt them.
GOOFSS can be found here.