With little nightmares mod you can add easily add all monsters to your world.
But better be wary because these monsters are not friendly!
Best Little Nightmares Mod For Minecraft PE
DISCLAIMER: This is an unofficial application for Minecraft Pocket Edition. This application is not affiliated in any way with Mojang AB. The Minecraft Name, the Minecraft Brand and the Minecraft Assets are all property of Mojang AB or their respectful owner. All rights reserved. In accordance with http://account.mojang.com/documents/brand_guidelines.
