Ralphie the Buffalo is the name of the mascot of the University of Colorado Buffaloes. She has been called one of the best mascots in collegiate athletics, and is often labeled male. The team of Ralphie Runners, who are varsity student athletes, run Ralphie on Folsom Field, the University of Colorado's football field before each half of home games. It takes five Ralphie Runners to run her around the field - two up front on each side to steer her, two on each side to help guide her, and one in back to control her speed. Ralphie can reach speeds of 25 miles per hour. Females are used because they are smaller and less aggressive, although Ralphie has knocked over her handlers on many times before. Because of this, whether or not Ralphie runs is at the discretion of her handlers, and her run may be canceled if she is unusually nervous or upset.
The tradition began in 1934, three weeks after the selection of Buffaloes as a nickname for the University of Colorado in a contest by the school newspaper. A group of students paid $25 to rent a bison calf and a cowboy as his keeper for the last game of the 1934 season. The calf was the son of Killer, a famed bison at Trails End Ranch in Fort Collins, Colorado. It took the cowboy and four students to keep the calf under control on the sidelines during a 7–0 win at the University of Denver on Thanksgiving Day. Live bison continued to make sporadic appearances at CU games, usually in a pen on the field or driven around in a cage. In the 1940s, the school kept a baby bison in a special pen. The first named bison was "Mr. Chips," who appeared for the first time at the 1957 CU Days kickoff rally.
Ralphie rarely travels to away games and does only when permitted by the rules of the host stadium. Ralphie IV traveled to the September 23, 2006 game against the Georgia Bulldogs along with an ESPN producer and cameraman who documented the trip and aired a special on that weekend's College Gameday. She also traveled to the 2005 Champs Sports Bowl. She wears a custom-made banner that reads "GO CU" on one side, and "Beat [the other team]" on the other side with the CU Logo, such as "Beat Nebraska." Ralphie travels to games and appearances in a black custom stock trailer emblazoned with her name in gold. Ralphie and her trailer are pulled though the University Hill neighborhood before games on her way to the stadium.