Boo (Mary Gibbs) is one of the main character in the 2001 film Monsters Inc.




Real Name

Mary Gibbs


2 1/2 (Monsters Inc), 3 (Castaras) 18 (Castaras Long After)

Date Of Birth

6th August, 2OO9



Home world


Hair Color


Eye Color


Voiced By

Mary Gibbs (2OO1-2O17)

Created By

Pixar Studios

Role In MovieEdit

Boo appears halfway into the film when she is seen curiously staring at Sully's tail while being let loose in the factory. At first Sully is afraid of Boo, as monsters believe that humans are toxic (but they are not!). Sully and Mike then hide Boo from the CDA. The next day it is revealed thats it's not only the CDA thats looking for Boo, but Randall is looking for her too.

Later on, Mr Waternoose, The factory owner tells Sully that a scaring session is starting to show his new scare recruits the art of scaring. Mike and a disguised Boo show up, but unknown to Sully, Boo stands next to him and scares the girl to death, which makes Boo sceard of him and she runs away, only for her hood to fall off. Later, it is revealed that Waternoose was involved in Randall's scheme to kidnap Boo and banish Sully and Mike. Boo forgives Sully and is rescued.


Boo will appear in the 2017 cartoon crossover Castaras, as a goodie. Her villian is Mr Waternoose. She hangs around with Nibbles Mouse and Pebbles Flinstone.

Castaras BabysEdit

Boo does not appear in the cartoon.

Monsters UniversityEdit

Boo does not appear


  • It is unknown how old Boo actually is, she may be a two year old child
  • It may be known that Boo has a delayed speech inpediment as she just babbles
  • She doesn't act her age, if she is 2, she has the mind of a 12 month old baby.
  • Many fans beleive that Boo is actually 4 years old with a growth problem and with bad speech
  • Boo may have 4 older brothers, who tease her because she's young and a girl.
  • She is a asian descent
  • She has a Jessie doll

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