In 1885 P.T Barnum was a trustee of Tufts University and donated the stuffed Jumbo to the school after it died in a train accident. The elephant was placed in Barnum hall and was popular among the students. Coaches would even refer to its strength and power in pep talks for games. Since then Jumbo became the official mascot.
in honor of a major donation from circus owner P.T. Barnum in 1882. http://en.wikipedia.org/wiki/Student_life_at_Tufts_University