Leon was sea-salt ice cream. He was cold (even to his friends, usually) and slippery (but only if you didn't handle him right) and he didn't ever fit into just one category (you could spend days trying to figure out what he was and still not succeed).
Leon was salty (stings-your-mouth salty, swift-kick-in-the-taste-buds salty) at first, but then he was sweet (almost-not-there sweet, light-and-airy sweet).
Leon was sticky (can't get rid of him, but who wants to?) and staining (he'll rub off on you) and if he was mass-produced it'd be the best (or the worst) thing that ever happened.