McDonald's Shamrock Shake is back and marks its annual return with a special reunion to support a meaningful cause.

McDonald’s fans, brace yourselves because the food chain is about to reintroduce its seasonal classic—the Shamrock Shake.

In honor of the 50th anniversary, McDonald’s is also reuniting two beloved members of the McDonald’s family for the first time in decades: Grimace and Uncle O’Grimacey. And if you need a refresher, ...