Make sure you have The Extra Details Add-on Above Better Endermen
Spawn in Lush Caves
Requires the Extra Details Addon
Better Endermen
Spawn in The End
Extra Details Add-On, Un-zip "Better Endermen.zip" open the Un-Zipped Folder, then once you're in there open "ADDONS" then drag and drop the Addon into your resource pack folder, when using the packs MAKE SURE the Addon is located above the main pack
Spawn in End Highlands
Spawn in Swamps and Mangrove Swamps
Spawn in The Overworld
Spawn in The Nether