It's simultaneously amazing and horrifying seeing all the various ways people utilise Minecraft these days, but I'm not quite sure what category "razing an entire world to the ground with a vicious army of tiny axolotls" falls into.
YouTuber GrayStillPlays is no stranger to doing the weirdest stuff with Minecraft, having an entire series dedicated to breaking the game in all sorts of ways. This is by far my favourite though, with Gray's goal being to take his horde of amphibians and use them to kill the ender dragon.
A Minecraft axolotl joins his army every 30 seconds, and each one eventually levels up and gains new abilities, they quickly go from being adorable walking fish to frightening monsters, capable of shooting arrows and causing massive explosions with a mere chomp of their tiny teeth. Things get rough when Gray tries to trade with some Piglins for ender pearls, with the axolotls seemingly so thirsty for blood that they start killing everything in sight. But he manages it, and it's genuinely quite awe-inspiring watching how quickly the ender dragon goes down at the end of it all.
It's not a challenge or a speedrun, but the whole thing is mighty entertaining nonetheless. I always enjoy seeing how people take games to create new, interesting experiences and this is no different. It's worth the watch to see the evolution of these murderous critters for yourself.