This story is old, but it is amazing to me. I seen this on 'Animal Planet' on the computer, the story of this. A lion who 'adopts' baby antelope. Lion and antelope Adopting other ones
During the show, it even showed her trying to 'call' the baby, doing the vocal sounds lions use to communicate with each other. It showed her in some time acting like the baby is her prey, her like 'nature instinct' coming out, but she never killed or hurt the antelope. It is just amazing thing of 'unnature' I guess.