Linden bears are, literally, in-world created teddy bears designed primarily by Linden staff. Nicole Linden started the process of creating Linden Bears, and many, if not most, Lindens have their own bears available for the asking. There are also collectible boxes, mugs, shirts, and cards, but the bears remain the sentimental favorite.
Not all Linden bears are, in fact, bears. At least one is a duck rather than a bear, while another is a lion. Some even vary wildly from a bear shape, such as the one created by Torley Linden. Most, however, are modified from a basic bear shape.
There have also been special event bears, such as a "Million Member bear," holiday bears (U.S. Independence Day, Valentine's Day, Easter, St. Patrick's Day, Christmas, etc.), and a bear touting the inclusion of flexible prims and local lighting in Second Life Version 1.10. These are some of the rarer ones to be gained, requiring inside knowledge, luck, or both to obtain.
One can get one of these bears by asking their creators directly, or finding a bear and box distributor within many Linden-owned sims. With special holiday bears, one usually needs to seek out Lindens with Holiday themed names, including Cupid Linden, Leprechaun Linden, Bunny Linden, and TrickOrTreat Linden.
List of Linden Bears Past and Present Linden Bears