The new McDonaldland shake, depending on which size you order, runs between 510-900 calories. Here's what it tastes like.

McDonald’s Happy Meal is back with its exciting toys and meal options to satiate all your cravings. McDonald’s is bringing two beloved pop culture icons in a limited-time Happy Meal. It features Hello Kitty and Teenage Mutant Ninja Turtles (TMNT)!

Starting Aug. 12, the chain will launch the McDonaldland Meal, an adult Happy Meal of sorts featuring either a Quarter Pounder with Cheese or 10-piece Chicken McNuggets, fries, a collectible souvenir and the new Mt. McDonaldland Shake, which features a mystery flavor the company is encouraging diners to figure out.