When they spawn, they are invisible and do not have a hit box, but do have sounds and can attack. Their spawn eggs also do not show up in the inventory anywhere, and they cannot be summoned. This goes for all four mobs. I have tried uninstalling and reinstalling the mod. I am using 1.10.2

I'm going to need a full log if I want to even attempt anything here. In any case, 1.10 isn't supported, and this issue is substantial enough that someone would've noticed by now, so I can only assume you have some other mod messing something up or have a client-server desync in the files or configs.