The Temptation is much easier to understand when you look at it this way:
Although, yeah: the snake body thing should have been a dead giveaway.
Think about it, though: we have nasty visual images of Satan in our mind because artists need to convey evil visually, but Paul tells us that Satan himself masquerades as an angel of light.
Or, as Frodo observed, “I would think that a servant of the Enemy would look fairer and feel fouler.”
H/T Eric Kwakkel