Rocky is one of those rarest of all creatures -- he can sing, but not speak. He's the sexiest science project ever (two possible exceptions: Kelly LeBrock in Weird Sciene and Benedict Cumberbatch in Frankenstein), the mysterious Dr Frank-N-Furter's desperate attempt at building the perfect man, one who is both an exemplary physical specimen and utterly devoted to his creator. Naturally, things don't go exactly as planned, because although Rocky has a certain amount of loyalty to Frank, that doesn't stop him from having sex with Janet. He's one eighth of an immensely convoluted love octagon, despite the fact that he doesn't seem capable of mastering the power of speech. Then again, when you look like Rocky and you wear a tiny golden speedo, no one would even be paying attention to what you said anyway. He's the glam rock, outrageously campy version of Frankenstein's Creature, and sure, maybe he's not the most loquacious character in the movie. But his name's in the title, and that's got to count for something.