On PC, there are unofficial mods you can use to get some of these achievements (like Cats Vs. Dinos or Boss Hunts) but you still can't get Community Challenge achievements. ☹️
You can get the Cats Vs. Dinos and Boss Hunt achievements with the mod Private Play Remastered. You will need Frosty Mod Manager (available here) and the mod file (available here and here)
You can get some of the unobtainable achievements through mods that let you play the gamemode, but that's PC only. If you play on consoles you won't be able to 100% the game. If you want the mods I was talking about, check my reply before this one.
(CM: Multiple posts merged. Check out this post for tips on how to edit and add more to a post.)
