How about some unusual combinations of tank mates? I used to have an Oscar and White Cloud tetra. The WC would follow the Oscar like a little puppy and the Oscar never ate him. I only fed the Oscar pellets and frozen food so maybe he didn't realize the WC was supposed to be food. I like to think he was just looking after his little buddy.
The white cloud died after about a year ( of natural causes?) and I was going to try another WC. I bought the new WC but while I was floating the bag in the tank the oscar was trying to eat him so I put him in another tank. I would love to hear more stories of this kind of thing.