There is an interesting article on BBC, 'How Egyptian god Bes gave the Christian Devil his looks.' There, Alastair Sooke tells about Bes' physical traits and traces them, via Pan, to the Christian Satan.
Bes, it seems, was not an Egyptian state-sanctioned deity, but he was very popular, associated with drinking and singing, sex and birth. "Although to modern eyes he may appear frightening," Sooke writes, "he was actually decent. Friend to beer-swilling carousers and expectant mothers alike, he warded off noxious spirits like a gargoyle on a medieval church."
Phoenicians and Romans would eventually come to accept Bes, and his amulets became commonplace. It is through this contact that many of Bes' characteristics would influence the depictions of satyrs.
This, in turn, influenced depictions of the Devil:
There are obvious similarities between Satan and his sylvan forebear, the raucous Greek goat-god Pan, with his beard, hairy haunches and cloven feet. Like Bes, Pan was associated with prodigious sex. "The Church did to Pan what Stalin did to Trotsky," the art critic Robert Hughes writes in Heaven and Hell in Western Art. "The attributes of Pan were given, in art, to the Christian Satan."
Sooke writes that Bes was sometime portrayed with a forked tail or serpents emerging from his body, such as we see in the baptistry in Florence.