Should I adopt my friend's cat?

Okay, so my friend found these 2 cats in a box left somewhere by this man for 2 hours so he decides to take them in because he doesn't want them to die on the streets. He needs someone to adopt them and they're so cute. I'm afraid of what'll happen if I adopt them. I have these weird thoughts of them being mutant and stuff because I watch too many shows... o.o" I really love cats and want to befriend them, so I don't know...