When an ice cream truck's jingle breaks down, Megablast is happy to help by playing the sickest jingle of all time. The band draws so many customers that the truck sells out of ice cream - meaning the town brat and villain Stewey doesn't get any. He throws a tantrum and becomes Gooey who uses ice-slime to turn everyone into freeze-brained minions to rip the town apart in search of ice cream for him.