McDonald's is bringing back a character called Uncle O'Grimacey to help sell their Shamrock Shake drink. The shake comes out every year around St. Patrick's Day and this time, 25 cents from each sale will go to charity. This move is to help boost sales after a tough few months since a health scare. This is the third time they are using old characters to market their food. Grimace, a purple character, has been a big hit with customers. He even helped a baseball team win games last year! Uncle O'Grimacey wasn't used for a long time, but he's back now to help out. There was a rumor about why he disappeared, but that's not true. Remember to try the Shamrock Shake and support a good cause!