“In the second place, the primeval man was round, his back and sides forming a circle; and he had four hands and four feet, one head with two faces, looking opposite ways, set on a round neck and precisely alike; also four ears, two sets of genitals, and the remainder as one would imagine. He could walk upright as men now do, backwards or forwards as he pleased, and he could also roll over and over at a great pace, turning on his four hands and four feet, eight in all, like acrobats going over and over with

Source: Plato’s Symposium 189a-193e: Aristophanes on the Nature of Love | a classical blog