After a football game in 1921, a reporter wrote that Gonzaga fought tenaciously like bulldogs. Thus, that description became the new mascot.
Over the years, Gonzaga has had numerous live bulldogs as mascots.

Human mascots replaced live dogs in 1980. Lee Mauney, a student from Hatchie Bottom, Mississippi, introduced the Gonzaga crowd to the first costumed bulldog mascot in 1985.

Well in my opinion, they should have never moved from four legs to two.
The four legged mascot will always win from a human in whatever costume.