"Bison Bison had had had had had Bison Bison Bison shi shi shi." is a red text modifier on weapons in Borderlands 2
Found on the following red text weapon: Siah-siah Buffalo, (or any other version of the Buffalo Sniper Rifles) which you get for completing the mission "Demon Hunter".
Grants Weapon Effects[edit]
Weapon skin has no scope
Increased critical hit damage