Bat Wing

Bat Wing (BW) is a reagent that is in use on Pagan, harvested from -as the name already says- bats, by cutting off their wings.

Pagan
On Pagan, Bat Wing was used in the magic scool of Thaumaturgy for the magical effect of affecting or creating life/creatures. Interestingly enough, despite Mythran selling the reagent, no live bats were ever seen in the entirety of the Avatar's stay in the world.

Ultima Online
Bat wings are also used as a reagent in Ultima Online for the school of Necromancy.