That’s because “jelly ball” is a nickname for a type of jellyfish What is a jelly roll used for? what is a jelly roll urban dictionary. Are jelly balls in the ocean poisonous? They’re harmless, small, and among the least venomous of all jelly species, and they’re particularly abundant on the southeastern seaboard. According to Hanna Raskin of the Charleston Post and Courier, jellyballs are “bland at best,” and they’ve often been subject to culinary derision. Read More...