Besides the mobs mentioned there are also a few others. The mutant skeletons know how to ride a mount. Pocket Manager for Minecraft. You can find them in the spawn egg list further down or discover them for yourself in-game. Mod Maker for Minecraft PE.
Lea. Age: 30.
Transport mod for Minecraft.
Anya. Age: 32.
Mutant creatures mod minecraft
The mutant creatures spawn randomly in-game, but their spawn rate is very low. Here you can see them riding a mutant spider. All of the mobs use customized mob models to provide a new and hopefully more scary experience.