There's one mask in particular that sticks out to you, a black furry monster mask, with large yellow fangs, poking out from thick, dark lips. Besides the fangs it almost looked human except under layers of thick hair. You quickly slide it on and head over to a nearby mirror. It's a decent looking mask, it'd make a nice haloween costume piece. You stare at yourself longer and longer finding yourself more and more pleased with it, soon becoming unwilling to ever take it off. You start feeling itchiness acrossed the hair of the mask, not realizing that you shouldn't feel this and that it isn't your hair you start scratching furiously at your new face, pulling out a massive louse that had made its home in your new mane. You hold it between your fingers as it tries to wriggle free. You feel the rest of the colony move around your head. Suddenly without a second thought you pop it into your mouth, the mask fully conjoined with your face, opens up. You crunch the bug between your teeth as you devour the insect whole. You start feeling warm and strip naked in an effort to get as cool as possible, exposing your rapidly changing body to the cool open air. You grow about a foot taller and much fatter. Thick, filthy black fur covers your body, and is quickly infested by the same bugs that were crawling on your head. You're hands and feet grow massive, with sharp, dirty claws dotting each finger and toe. You reach down and grip your cock with your new massive hands and it has almost tripled in size, with a pair of orange sized balls to go with it. You feel your hairy organ harden in your hand as you stroke it as you soon start gripping it harder and harder, furiously masturbating onto the bathroom counter, releasing a torrent a thick cum all over it, resulting in the most pleasurable feeling you've ever felt. You let out a loud animalistic roar of pleasure, signaling that there was no humanity left in you, you're a monster know, and it's time to act like one...