A kind of faux five
when you're going in to give someone a high five but quickly pull away, making your hand make jellyfish motions in the air while saying, "JELLYFISH!"
To add to the affect, apologize, then go in for a hug.
When they go in for the hug also, pull back and make the jellyfish motions with your arms while saying, "JELLYFISH!"
Known to be annoying as hell.