Imagine just how traumatic the death of Nestor's mother must have been for Nestor. He would have woken up the morning after the storm to find his mother's lifeless, frozen body on top of him, and then had to climb out from underneath her and bury her in the snow himself.
How would Nestor, a donkey who lived roughly 2,000 years ago, still have descendants today in the form of Spieltoe? And moreover how did they reach the North Pole? Then you remember that Olaf, whom Nestor returned to at the end, is a donkey breeder. And what else would a donkey breeder do with a donkey who now garnered a massive level of praise and admiration? Nestor obviously grew up to be a VERY promiscuous stud...
