Silk Spray (3.5e Feat)
From D&D Wiki
Author: Nari Mortem
Silk Spray [Racial]
You can throw a silk spray on a flying creature to make it loses its Fly property.
Prerequisite: Nerubian, character level 2
Benefit: Nerubian can throw a silk spray three times per day. This is standard action with DC is 10 + 1/2 character level + ability modifier (Dex), but has a maximum range of 60 feet and is functioning for 1d6 rounds, and is effective against targets up to one size category larger than the Nerubian character. Silk spray may be used, but doesn’t work with target without flying. Target must make a Reflex save throw and if the save fails, target with flying loses its Fly property and floats downward. Target can use its other speed properties if these properties don’t allow it to fly.