Egg Tab - Forge
Click here for the Fabric version of this mod.
Egg Tab is a client-side Minecraft mod that moves all mob spawn eggs to a new "Spawn Eggs" creative tab. It also adds an "Enchanted Books" tab. Both tabs can be toggled (through config file). This mod also works with mods that add additional spawn eggs.
Requires Mixin support (latest Forge version or MixinBootstrap)
Note: This mod might work on older Minecraft versions (tested on 1.15.2 too) but I'm only providing support for the version shown on the download page.
Here is a picture showing the tab in action: