Inspired by Junji Ito's work "Hellstar Remina". Go read it, it's absolutely nuts! So, we've got non-threatening Japanese Love planets, and we've got tons of interesting assets. Problem is, there's no sense of fear or threat. So, let's have a fun change of pace; Hellstar. The Hellstar would be a planet of Corrupt Dirt and Flesh only. It'd be a massive living creature that randomly moves through the X-Sector, and appears near any star or planet at random after travel. If it appears near a planet and is not landed upon, the planet will be destroyed next time you visit it. For example, the entire upper layer of the planet could be gone, and all that's left is the cavern and core layer. The destroyed planet's biome would change to "Desolate", and have the space background because the whole atmosphere was removed. It'd be a planet the size of a Gas Giant, for that sense of threat. To defeat the Hellstar, you need to find and destroy a certain number of important parts, like a brain stem or a billion eyes. Once defeated, the planet remains in orbit around where it was defeated, allowing you to colonize or terraform it.
Okay I like your general idea I don't want to say my idea here because its a long one ill start a new thread and mention something like this if you even care about it you can follow me and see this post im making in Microsoft word ill post it in a day or an hour depends (basically im making a long post of ideas this post gave me one to add) +1 to you good sir
I like the idea, minus it destroying planets as that could force you to land on it when you are not ready just to not lose your base. If it was restricted to a hardcore mode or it only happened on planets that have never been traveled to before I am fine with it.
I go the whole hog and just call them "hentai planets" when I'm with friends. The idea of a planet-sized boss sounds cool.