Well I’ve never kept one, but I am planning a tank around one down the road, so I’ve done a bunch of research on them, in general faster more boisterous small fish will have a better chance of evading him, but the fish aren’t the first thing he’s going to go for if the fish food isn’t keeping him full... don’t keep any expensive inverts... but if you have a bunch of hermits and snails (preferably types that’ll reproduce in your tank) he’s much more likely to go for those first. It’s a c**p shoot with fish though, there’s no telling what is going to look the most tasty to a particular fish, just because the species as a whole tends to go one way doesn’t mean you won’t get the one fish that doesnt follow the stereotype... just try to keep most of his tank mates at least half his size, if you’re going to get any Little fish stay away from the slow, shy and timid types. That’s my plan anyway.