Depending on the level and when you come up to it depends on what it eats. It will eat just about anything ranging from prime fish meat to berries to Giant Bee Honey. It’s a passive tame and might take a while so don’t stray too far!
One thing I have noticed is that the food they ask for resets after a certain time. So a Moschops that asked for Cooked Prime Fish Meat may ask for Tintoberries when you pass by again. So if you see one you want to tame just check on it every so often and see if it is asking for.