Very similar to grimy trout. Except someone gets on hands and knees behind someone and puts their head in-between the other person's legs. Usually a male. Before splitting your buddy's legs with your cranium yell "Grimy Grizzle" and the proceed to go in-between so named fratstar's legs and move your head in a side to side motion and growl like a bear. If you feel flamboyant go up and down if you want. After doing that pull out and then stand up and say "Hey no homo though" and all is good.

Got the covid-19 vaccine