A mild to severe stalker. This person can stalk you on the internet, or via email. This person may be occassional walk or drive bys your home...they may even go as far as sending you flowers at work.
Yet, though slightly creepy there is something endearing about the Bunny Boiler.
As used in a phrase:
Chick: Correct me if I'm wrong but aren't you the same guy that sent me flowers a few years back?
Miguel: ...it is not like I boiled a bunny and hung it outside your window.
Chick: Stop emailing me Bunny Boiler.
Miguel: Not nice.