Occasionally, Alliance of Valiant Arms will create a series of A.V.A-born weapons, all based on the same theme, whether that theme be an animal, a seasonal event, or something completely different. Weapons following these themes will have an altered exterior to match.
Weapons will very rarely have their statistics altered (usually improved) as a result of being part of a themed series. Most of the time, the weapons are just cosmetic variants of an existing weapon.
The Black Bear theme gifts its weapons with what is described as a "roaring bear design", and that "enemies [will] be frightened to death". There is just one weapon with altered statistics: the SA58-Para Black Bear. The other two weapons in this category are cosmetic variants. Typically, the weapons in this series are won (some permanently) through the spending of Aeria Points on the loot wheel, and applicable tiered spenders.