I know this is way off topic, but here's your Grimace history. It looks like he disappeared when the McDonaldland commercials came to end end. That dumb purple thing was my favorite!
Grimace was a character featured in McDonaldland commercials. He was a large, purple anthropomorphic being of indeterminate species with short arms and legs. He is known for his slow-witted demeanor. His most common expression is the word "duh".
Originally, Grimace was the "Evil Grimace", with two pairs of arms with which to steal milkshakes. After that first campaign, the character was revised to be one of the "good guys", and his number of arms was reduced by two.
Commercials and merchandise generally portrayed him as a well-meaning simpleton, whose clumsy antics provided a comic foil to Ronald McDonald. The character was retained after the streamlining of the characters in the 1980s and was one of the few members to also be retained until the end of the McDonaldland commercials.
He had an unnamed mom, an unnamed dad, a grandma named "Winky", a great, great grandma named Jenny Grimace, a possible brother named King Gonga (who rules over all Grimaces).
Grimace was last seen at Dodger Stadium on July 18th, 2012 vs. the Philadephia Phillies, dancing to Ram Jam's 1977 classic, Black Betty.