A fictitious yoga pose which requires incredibleflexibility where a person shoves their head up their own ass. Used mainly toward arrogant yoga aficionados.
Girl: Yoga is so good for your heart and soul; it's way better than lifting weights.
Guy: Oh yeah? Well, why don't you go perform the backwards tortoise then, bitch.
A Rigamortis Tortoise is a vile and disgusting creature. Often cold and calloused, Rigamortis Tortoise can disgust even the most hardcore of people. Rigamortis Tortoise often has an undeserved sense of entitlement caused by birth.
We caught Rigamortis Tortoise walking out of the morgue with a bottle of astroglide and a pink dildo. That disgusting vermin.