The Rude Guy is actually the second character to make an appearance in How to be a Werewolf. Malaya Walters is seen handing over change to a customer and was about to greet the next when he approaches the counter. In what is very nearly an assault, he accuses her of failing to prepare his coffee drink to his exacting specifications: two regular shots, one decaf shot, easy on the milk (he claims she adds too much), four pumps mocha and less than an inch of foam, please. Of course, Malaya makes it right every time, but he's never happy with the first cup. He's been stopping by on and off over the past three years, and it's the same routine every time.
Nothing is really known about him, and the only time so far that he's been seen is in the coffee shop.