10 Movie Facts You Probably Don’t Know
7. Boo's Name Is Mary - Monsters, Inc.
Monsters, Inc. may be headlined by loveable monsters Mike (Billy Crystal) and Sulley (John Goodman), but who can forget its adorable human protagonist Boo (Mary Gibbs) - the young girl who Mike and Sulley attempt to return home before anyone notices.
While it's largely assumed that Boo's real name is never given, eagle-eyed fans have nevertheless started noticing a sneaky Easter egg which confirms otherwise.
During the scene where Boo draws while hanging out in Mike and Sulley's apartment, for a few fractions of a second the name "Mary" can be seen written on Boo's drawings.
This is presumably a nod to the fact that Boo was voiced by Mary Gibbs, the daughter of one of the film's story artists, Rob Gibbs.
And if you still had any lingering doubts about this being canon, the book based on the movie indeed confirms Boo's real name to be not just Mary but Mary Gibbs.