There are also mods that add all the mobs and mob variants from the now discontinued Minecraft Earth, like this one:
https://www.curseforge.com/minecraft/mc-mods/earth2java
I like having cool chicken variations
You might want to disable the Moobloom in one of them though since it's also covered in Friends and Foes.
Take the Nether for example, many biomes are absolutely crawling with Hoglins and Piglins that can and will gang up to kill you if you're not careful. However, when it comes to the Hoglins, their aggro ranges are not unmanageable, they make plenty of noise alerting you to their presence and you can even ward them off with warped fungus. The Piglins will mostly ignore you if you wear at least one piece of golden armor (at least until you open a chest or try to mine gold) and they also avoid soul torches. With the addition of the gold bartering system, the piglins are probably the most interesting mob in the game, simultaneously dangerous and helpful. I like how they feel like intelligent beings that kind of tolerate you showing up on their turf if you behave.
I hadn't played much with the big Nether update and I really enjoy the mobs and mechanics it introduced. By comparison, most of these hostile mobs just fly up to you from a continent away and kill you in three hits