If you wonder how Garuda got its names, then it is associated with the story of Garuda flying elephant and giant tortoise. Vibhavasu and Suprateka were brothers but they always fought over ancestral wealth. Both were saints but this did not deter them from fighting over property. They cursed each other, and as a result they were transformed into a giant elephant and a giant tortoise.
The animals were so huge. The elephant was six yojana in height and 12 yojana in length. The tortoise was six yojana in height and and 10 yojna in length. It must be noted here that as per modern calculation 1 yojana is equal to 12 kilometers.
The tortoise took refuge in a vast lake and the elephant lived on the banks of the lake.
The fight of two brothers continued even after transformation.
Their noisy fight disturbed the sages doing penance in the forest near the lake. Sage Kashyapa, father of Garuda, asked his son to eat the elephant and tortoise so that he will have his food and the sages will no longer be troubled by these gigantic animals.
Garuda took both the animals and flew to heaven and placed them on a tree there and started to eat them. But the trees of heaven could not bear the weight of the animals and they prayed to Garuda to take them somewhere else.
Garuda took the animals and flew looking for a suitable tree. After long search, Garuda saw a tree which was 100 yojana in breadth. The tree gave permission to Garuda to eat on its branches. When Garuda sat down on the tree, with the elephant and tortoise, the branch of the tree broke.
Garuda soon noticed that saints known as Balakiyas were doing upside down tapas on the branch. He immediately took hold of the branches and flew from there along with the elephant and tortoise.
The rishis who saw Garuda flying with such enormous weight named him Garuda. One who flew with unimaginable weight.
It is said that Garuda later placed the tree branch safely. But the tortoise and elephant still continued to fight.
They continued to fight in his beak; they fought even when they are held in his claws; they fought when they were placed on a rock. Garuda finally ate them, and even as they passed through his throat, they continued to fight. And even when they reached his stomach, they did not stop fighting. Finally, they were consumed by the fire in the stomach of Garuda.