Animal: It's rather between the Fox or the Frog, cause I'm a huge fan of frogs IRL. And the ones in Minecraft me of fat bullfrogs, which, how can you not love? Foxes are cute but I like them to cause even though they're not really tamed they still fight monsters if one attacks you.
Monster: Evokers, Though I'm not so much of a fan of the Vex they spawn. I still think they're the most interesting of the illager race and I hope to see more from them.
Boss: Enderdargon, still hoping for an End update soon cause I really hate how this is supposed to be the final boss of Minecraft but at this point, you can kill it with ease with some Netherite tools and a few beds. Hopefully, MoJang has some sort of plan for it soon.
Overall: Villagers, I normally don't play on multiplayer (cause I hate people) but having these NPCs around my base gives more some sort of company even if it's just them wandering around in circles.