Something on your leg. When you took a look, you found that your shoe, and sock has melted on your left foot, and the cause of it was a sludge of dark brown goo substituting as some piece of clothing. You were completely caught off guard by what happened, as you begin to wonder what happened before you came to the gym.
You try to use your other shoe to remove the goo from your leg, but instead the good melted the other shoe, and sock, leaving you completely barefoot as the goo began to crawl up your legs. You had no idea why they began to do that, but you saw that they left your feet completely naked, and the goo wasn't really melting your skin. In fact, when you felt the goo on your legs, it completely felt more like fur thangoo when it was hardening to your legs. Just then, you feel the fur crawl up your thighs.