Black Garuda has a bird head, wings and claw legs. The torso and arms are human-like and he holds a naga serpent with the hands and bites down with the beak. He is accompanied by eight retinue deities. This form of Garuda arises from the Siddhaikavira Tantra (see below).
84000: Translating the Words of the Buddha: Siddhaikavīra Tantra (Siddhaikavīratantram, dpa’ bo gcig pu grub pa zhes bya ba’i rgyud kyi rgyal po chen po)
Chapter One Second Mantra 1.8 oṁ garuḍa haṃsa he he cala cala svāhā |
Oṁ, garuḍa! Swan! Hey, hey! Move, move! Svāhā!
The mere thought of this king of mantras will stop a hailstorm. By inscribing it on a kettle drum with chalk and chanting over the drumstick, one can then use the sound of the drum to stop a hailstorm. The same can be done with the sound of a conch, etc.