Teddy bears have been a standard part of every Call of Duty game since the original on PC. So it should come as no surprise that Infinity Ward and Sledgehammer Games would include them in Call of Duty: Modern Warfare 3.
Here, Ray from Achievement Hunters shows you how to find all of the teddy bears in the multiplayer aspect of the game. However, there's no achievement or trophy attached to finding the teddy bears. Regardless, it's still cool to see an old tradition carry over to the Modern Warfare series, even though they've been delegated to being nothing more than Easter Egg.