Set you on fire: PyroManiak, because...well the name says it all.

Punch you: Magus of Zeal, because he's foul.

Kiss you while you’re unaware: I wouldn't kiss and tell.

Kill Santa: Bunny, because Easter vs. Christmas.

Destroy the earth: Goldenboko, because the world would crumble when everyone discovers that gold isn't the new black.

Try to destroy the earth but fail: Christmas, because she's full of HATE. But, she would fail by getting distracted by Old Manus.

Turn out to be David Hasselhoff: DK, because of the ENDLESS CROTCHES.