Sephiroth is not used to people being that close. The only time anyone is, with such a threatening aura, is when they absolutely mean harm. The genuine clown suit doesn't even weigh into it as he immediately uses his own frame to hide the plate of delicious meat variety as if it might be stolen from him, a low, rumbling growl rising.

An actual growl. It's not a metaphor, it's the sound an annoyed animal (or a dragon) might make. "Step. Back."

Vegetables are a perfectly reasonable idea, but first he's going to protect what he has.