Mutant Creatures adds 20 mutants along with minions and easter eggs with incredible powers... If you are looking for an add-on to increase the game difficulty a few notches then this is a great option. This means that the world will be a lot more difficult as each mutant is much stronger than its predecessors. Neither of the mutants gets affected by fall damage or knockbacks.
Mutant Bouldering & Lobber Zombie: Mutated beasts but they look oddly different. Two ordinary zombie that was a part from Minecraft Earth that got discontinued in mid-2021. They don't have any special abilities like summoning minnions but they prefer what they have. Lobber Zombies throws their poison flesh while Bouldering Zombie climbs with its buffed Arms on walls like a spider.
Mutant Creeper: The beast with four legs and a crooked neck making them look similar to a spider, but a little bit scarier. Previously creepers were afraid of ocelots but as a mutant, they take their revenge. They cause much greater explosions, summon its minions and immune to explosions! Once defeated at low health, just run!
Mutant Iron Golem: A powerful golem beast that is very like the warden. It doesn't spawn naturally but it's a gift. It can take down multiple mutants at full power, but after harsh battles it well need to be repaired over time. Up to 2 players are able to ride it but the beast doesn't go at full power.
And more Mutants in mod.

Disclaimer: This is an unofficial app for Minecraft Pocket Edition. This app is not affiliated in any way with Mojang AB. The name, brand and assets are the property of Mojang AB or its respectful owner.