With this plugin you can quickly find chunks with a large amount of Monsters, Animals or even Tile Entities like Hoppers in it. Very useful if you want to find XP-Farms that accumulate a large amount of mobs or that one infinite chicken or villager breeder that brings your server to its knees!

Plugin Link:

https://www.spigotmc.org/resources/entitydetection-tile-entity-support.20588/