I read this article from the site below and liked it very much. It did give me answers to few questions which has been nagging me for some time.
Just reproducing the article in full without any adulteration with my thoughts. I felt that the article is written so nicely please give all the credit to the site and its author.
High in the reaches of Mount Kailash is the abode of Lord Shiva. One evening Lord Vishnu, came to see Shiva. He left behind at the entrance Garuda, the half-man, half-eagle composite, who served as his vehicle.
Now, in the ancient Hindu thought, even a slight glance of Yama is said to be the harbinger of death. Garuda, who had observed Yama’s action, told himself, “Yama looking intently at the bird can mean only one thing – the bird’s time is up. Perhaps on his way back he will carry away the bird’s soul with him.” Garuda’s heart was filled with pity for the helpless creature.