A large herd of roaming freshman typically found on a college campus. There is usually an alpha-male present, i.e. one member of the pack who has connections to elder members of the campus, thus allowing the frosh pack to drink at the elder's watering hole.
A frosh pack, although usually docile, may become more aggressive as the night goes on and the drinks go down. As a result, approach with great caution and never look the alpha-male straight in the eye.