In this mod there's a mob called CobbleMob that can spawn randomly: in plains. It's not dangerous, but that's not all; it has weapons: a pickaxecobblenite and a Cobblenite ore The player cheat spawn is in the same place as the CobbleMob, so in the plains.
The mod is made of stone, so it's very resistant, and you can even see its health in the mob bar at the top. It might take a while to kill, but with a netherite sword, it can be easy.
This is a pickaxe made from Cobblenite ore. It's gold tier and can only be found in Creative mode, but one day I'm going to make a Cobblenite block that will be found in caves.