Firstly, yes I'm on a Godzilla binge... and it got me thinking! How about adding super rare Kaiju size mobs to large end-tier planets? It'll be a boss/event too. If one's on the planet and you run into it it triggers an event where the ui scales to it's size for visibility and added "dayum that's huge" effect and epic battle music starts playing. Kaiju could be based on normal mobs, so there's small, large, flying, aquatic, but use their own unique part sprites so not to be juuuust super big normal mobs. While the Kaiju fight goes on it'll have a fear effect against all other mobs/npc (except guards maybe) so while you run/fight from it they don't trip you up. They'll be slower so not to over take you too, but have the ability to destroy placed blocks with attacks and maybe movement. Defeating a Kaiju would give you extra rare materials, maybe for unique monster hunter armor based on the sprite the Kaiju used! End-tier mobs for people who've fought all the bosses but still want a challenge could go hunt kaiju!