Nannerstein
The act of cutting a banana in half (leaving the peel on, of course) and approaching someone from behind with the two halves of the banana and smashing both halves against the person's neck, to create a "frankenstein" look with the two halves of the banana. Term coined by Johnny Szyperski of Spring Lake Park, MN.
See "definition" section for an example of how to "nannerstein" someone.