What is another word for jellyfish?

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 effect, 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.

Urbandictionary has several more definitions, most of them unprintable here.