Dark wings

Dark wings was a spell that caused the recipient to grow bat wings.

Effects
The spell caused the growth of bat wings from the shoulders of the caster or another person touched by the caster.

These wings had a tip-to-tip span of 15 feet (4.6 meters). They allowed only clumsy flight. However, their value lay in their strength. These wings could carry double the spell's recipient's body mass without problems and even triple of aforementioned mass could be securely made to land safely.

These winhgs were virtually indestructible. No amount of physical force could destroy them. They could be used in a defensive manner to protect the spell's recipient or other people through shielding them with the wings. They could also be employed in an offensive manner by buffetting others with it, but only in mid-flight and at the cost of dropped speed.

The spell had two drawbacks. First, the wings caused a drag that in turn caused the beneficiary's overland speed to drop. Second, once grown, even the creator could not make them disappear. The only methods by which to get rid of the wings were waiting until the spell expired and employing more magic like dispel magic or polymorph.

Components
The spell required somatic, verbal, and material components in the form of a piece of a bat wing and a piece of bone. The spell transformed the material components into the wings that grew from the recipient.

History
The spell was associated with the drow.