An old-timey McDonald's character is making a comeback this month—and we have all the details below. Can you guess who it is?

McDonald's is bringing Uncle O'Grimacey back to promote the Shamrock Shake. The chain has been reviving its McDonaldland ...

To mark the fan-favorite menu item's seasonal return, McDonald's is also reuniting its lovable purple Grimace character with his older and green relative -- Uncle O'Grimacey. McDonald's also ...

A promotional image of McDonald's characters Grimace and Uncle O'Grimacey holding the seasonal Shamrock Shake beverages. Uncle O'Grimacey, Grimace's uncle from Sham Rock, Ireland, debuted in 1975 ...

A McDonald's character who hasn't been seen in decades ... that Uncle O'Grimacey - the green-hued uncle of fan-favorite character Grimace - would be making a 'special Shamrock visit.' ...

Uncle O’Grimacey, Grimace’s Irish uncle, might not be as popular as his purple nephew, but he plays an important role in McDonald’s Shamrock Shake history. The St. Patrick’s Day character ...

After four decades, Grimace's long-lost Irish relative ... they were ripping off Sid and Marty Krofft characters, according to the McDonald's Wiki. Several of them appeared in a videotape series ...

Together, with our crew, customers, and iconic McDonaldland character, Uncle O'Grimacey, we're helping RMHC make families ...

One of the most recognizable holiday treats at McDonald's is making its return, along with one of Grimace's relatives.