Despite his hiatus, the green, furry icon was never forgotten. Uncle O’Grimacey earned his own merch line, called the Uncle O'Grimacey collection, which includes Shamrock Season pins, a crewneck and, even, a plain white tee that says “Who’s your uncle?” alongside an image of the uncle himself.

Grimace and Uncle O’Grimacey are welcoming the Shamrock Shake back to restaurants nationwide on Monday, Feb. 10

The beloved Shamrock Shake is coming back to McDonald's, along with a McDonald's character no one's seen since the 1980's: Uncle O'Grimacey.