Sources: Monster Manual
Monster Manual II
The creature can halt its forward motion while flying, regardless of its maneuverability.
Prerequisite: Fly speed.
Benefit: While hovering, the creature can attack with all its natural weapons, except for wing attacks. Some creatures may be able to make additional attacks while hovering, as noted in the creature's descriptive test. If the creature has a breath weapon, it can use the breath weapon instead of making physical attacks.
If a creature hovers close to the ground in an area with lots of loose debris, the draft from its wings creates a hemispherical cloud with a radius specified in the creature's descriptive text. The winds so generated can snuff torches, small campfires, exposed lanterns, and other small, open flames of nonmagical origin. The cloud obscures vision, and creatures caught within it are blinded while inside and for 1 round after emerging. Each creature caught in the cloud must succeed on a Concentration check (DC 10 + 1/2 creature's HD) to cast a spell.
Normal: A creature without this feat cannot halt its forward motion without falling. A creature with average, poor, or clumsy maneuverability can slow its flying movement to only half of its fly speed. (see Tactical Aerial Movement in the DUNGEON MASTER's Guide.)