Remember, Siddartha Gautama was reborn thousands of times before he was finally reborn as Prince Siddartha, destined to be either the world's greatest and most feared Emperor or a wandering beggar! He chose to be a penniless mendicant but an Enlightened, Exalted One!
The deeds of Buddha in his incarnations are part of Jataka, the book that relates the stories of his lives.
Before he was reborn as Prince Siddartha of Kapilavastu, in his last reincarnation he was a young man returning home during a snow storm. He chanced upon a starving mother tigress with her young cub on the verge of death as the mother was too weak to hunt.
In a last ditch attempt, the tigress leaped at the young man who stood still and allowed himself to be slain and eaten so the mother tigress could produce milk to suckle her cub!
It was this final act of love and sacrifice that allowed the young man to be reborn as Prince Siddartha who became Buddha!
And we can all be saved as the Buddha of the Future named Maitreya will one day descend from Tutisha heaven on the 9th plane to save mankind in our darkest hour of need!