I think the mobs you spawn with them should appear in dungeon chests, and they all have mobs in them right? Well, what I had in mind is that mobs spawned from eggs would help you (even chickens from the already-here eggs) like Creepers will act like wolves except have a higher attack and infinite (or set amount) of explosions and not be hostile to you unless attacked by you. Ghasts will fly around, and will shoot fireballs at hostile mobs, like snow golems, except higher attack and damage. (keep in mind they still cause fires) and skeletons act like ghasts except they dont fly and have a smaller attack and are more common. Well, Zombies will be more common, and act like normal zombies (except to you) and act like wolves. Endermen from eggs will help build/rebuild and silverfish will act as protection by hiding in wood blocks and chasing off hostile mobs. Enderdragons (if able to spawn from eggs) won't destroy terrain and will be ridable & controllable and if not being controlled while being rode, will take you to the stronghold. SPiders will make web traps to protect your house. (all are neutral. Zombie Pigmen will act like people and build houses. Slimes will act as pets.
Peaceful mobs:
they will all be ridable and controllable.
Tell me what you think, please.
Oh, I forgot one thing. They would be rarer than golden apples.
Clear some dungeons, then you get an unstoppable force of destruction, a very powerful minion, or ability to fly. Still OP.
this