Brief Teddy Bear History:
The Teddy Bear is an easter egg in Call of Duty: Finest Hour. In the level Surrender At Aachen (the third mission in the American campaign), go through the door and kill the four Germans. Then go to the area straight from the door that you came through. There will be an MP-40 and a teddy bear here. Pick up the teddy bear and you will receive health and a message stating "The Bear is adorable."
Teddy bears are used for target practice in the training level of Call of Duty 2 by the Soviets.
Several teddy bears are also seen in Call of Duty 4, especially in the levels, Blackout, All Ghillied Up and One Shot, One Kill. They were presumably abandoned by children when the city was evacuated in 1986.