An idea for a new boss from the mountain

so, i have a world were there is this gigant snowy mountain biome where i come across everytime i try to explore the world, and i though of adding a purpose to the biome by adding a new boss, therefore minecraft would have an underground boss, an underwater boss, a (kind of) nether boss, the ender dragon and now, a snow/mountain boss. This idea cound be done in so many ways but i though bringing back the iceolloger, which would spawn in a certain area around a statue. This statue is made of a material which you cant mine. When you kill an iceolloger, there is a low chance it can drop a key, which can activate the statue and start the bossfight, which I imagine being a three - five block tall pillager made of stone that throws big cobblestone blocks. I cant really think of anything that it can drop when killed, the best i could think of is an item that you can craft a powerfull weapon with, and, with other items, you can re-craft the statue to fight it again! I hope you read this and thanks for this amazing game :)