When cast, one of the caster's lower arms was transformed into a flexible appendage with a mouth at the end. The appendage resembled a snake. The mouth was filled with razor-sharp fangs. The length of the appendage was variable, from 1–14 feet (0.3–4.3 meters) in length. It could extend to its full length with incredible speed. The appendage's strength was the same as the caster's. The caster was able to use the appendage's mouth to grasp items. This spell could not be combined with any poison-based spells. While it was in effect, the caster could only case spells which had only a verbal component.