Initiate a 'high-five' with a friend, and when their arm is raised high enough, take your first two fingers (or strongest fingers) and jab them in the armpit, while shouting 'Giraffe Tooth!'. The doubled fingers resemble a giraffe's large tooth, and the action of jabbing in the pit is similar to a circumstance involving a giraffe jabbing his tooth into an armpit. This action is addictive and will catch on fast in your group of friends, family members, co-workers, church group, and etc.

A casual invitation / threat used by an individual that is not afraid of fucking someone up.