A Gayatri is a sacred prayer or mantra which is chanted in a specific form. Here is the Garuda Gayatri:

Om Thathpurushaya Vidhmahe
Suvarna Pakshaya Dheemahe
Thanno Garuda Prachodayath.

Om, Let me meditate on that great living being,
Oh, Bird with golden wings, give me higher intellect,
And let the God Garuda illuminate my mind

Here is a link to a Youtube performance: