Inspired from the movie Fatal Attraction when the mistress of Michael Douglas boils his daughters rabbit on his kitchen stove in a pot because he decides to stay with his wife instead of her.
Term used to describe someone you've just met and are casually dating only to find out later that they are "stalker material" and possibly psycho obsessed with you.
Friend: "Are you still dating that girl you met a few weeks ago?"
You: "No, she started driving by my house late at night when I didn't answer her phone calls and hacked into my email. Shes a bunny boiler!