A Garuda is a mystical animal in the Hindu religion. Garuda is a bird, or half bird half human, equipped with supernatural attributes. In the Hindu mythology the Garuda is the vehicle for the god Vishnu. Garuda is also an antagonist of the nagas, the mystical snakes who frequently appear in the Hindu cosmos - and in Buddhist temples.
The Garuda came to Southeast Asia with the early Indian cultures. In later centuries, when Buddhism was introduced in Angkor and the early Thai civilizations, the old Hindu mythology wasn't abolished but rather combined or intermixed with the new, more sober Buddhist teachings.
The origin of the Garuda in nature is presumably an eagle. As the eagle in many western countries, the Garuda is used as an emblem for powerful institutions as in the military or as state symbols in Indonesia and Thailand.
So, the Garuda is for example the emblem of the Siam Commercial Bank in Thailand. Garuda Indonesia is the biggest Indonesian airline. Garudas are also appearing often in temples, Hindu as well as Buddhist.
Image by Asienreisender, 2012