I just watched a show on tv, it was an animal documentary on leopards, and it was featuring this female leopard who sacrificed herself and mated with two leopards so that each would believe the cub is his and she would be able to have the den safely to protect her cub. And just nice she only gave birth to one cub, and while most mother leopards would abandon only cubs to try for a larger litter, she decided to raise her only cub. So then she went to hunt for food, leaving her cub in the den where hyenas and lions couldn't get it. But when she came back and called for her cub, there was no response and suddenly, she saw a python slithering away with her helpless cub's form in its throat. So she risked her life and spent hours tracking the python and attacking it all the way until it had a reflex to regurgitate and there was her poor dead cub, and she was trying desperately to lick it back to life but it was dead already, and she carried it away.

Saddest thing I've seen in forever.