Here is the Stanford Unofficial Mascot, the Tree:
Some history behind "The Tree"
In 1975 the Stanford Band performed a halftime show that suggested (in jest) several possible mascot candidates: the Steaming Manhole, the French Fry, and of course, the Tree. The Tree received so much positive attention that the Band decided to make it a permanent fixture.
For the first decade, the role of the Tree was generally performed by the Band managers' girlfriends; in the mid-1980's, however, the Band adopted a more formal selection process for its Trees. Today's Tree candidates must go through grueling and humiliating physical and mental challenges to show that he or she has sufficient chutzpah to be the Tree. During "Tree Week," candidates are known for performing crazy and apparently dangerous stunts; so much so that the University has felt the need to prohibit certain types of audition activities over the years.
The Tree costume is also a prominent target for rival University of California, Berkeley (Cal) pranksters. In October 1998, fraternity brothers from Cal known as the "Phoenix Five" stole the costume and held it "hostage" for two weeks.