Issue (The better the description the better i can solve the issue):

Since "Improved mobs" change the AI behavior of mobs in general, it will make Ender golems, ender guardians hostile towards farlanders and elder farlanders.
An easy fix one can do is getting into "Improved mobs" configs and adding them to the blacklist.

Steps to reproduce:

Spawn "Farlander" and "Ender Guardian", The guardian will proceed to kill their own kin.

Affected Versions (Latest is NOT a version):

• ImprovedMobs:

Other Mods (If you think it might be cause of an incompability. Adding a link + the used version will help greatly):

"The Farlanders" https://www.curseforge.com/minecraft/mc-mods/farlanders

Logs (Use a site like pastebin, gist etc. DONT COPY PASTE THE LOG IN HERE. Also dont upload the log file directly here!):

Config file (via pastebin, gist. No uploading directly):

you can blacklist mobs from the modifications via config. see the linked issue above for example