Galosphere-1.18.2-1.2.0-Forge
Modpack: https://www.curseforge.com/minecraft/modpacks/play-as-dragon

When you hover your eyes on Spectre the game starts to lag very badly with a drop in FPS (from 60 to 14). Perhaps this has something to do with trying to render it in the icon. When the GUI is turned off on F1, this problem does not exist. This only happens to your mob. Everyone else has no problem.
Before:

After: