Male dolphins, whales, and elephants are capable of grasping objects with um, er... "no hands."
This seems to be a feature only available on extremely bulky animals, which they have to enable to them to do the deed in spite of the encumbrance of their large size.
prehensile penis
(At first I thought this nodeshell was some kind of tasteless joke, but it sparked a memory of an article I'd read before, and I checked)
(now it's just tasteless.)