As I was flying thru an asteroid field (mining Void opals), I thought to myself "wouldn't it be really cool to fight some kind of monster in the asteroid field?". I was thinking something like the Chitauri Leviathan from Avengers Movies. Not too many Leviathan so that you are constantly running from them and not mining, but enough to allow you to hunt/be aware for them. Also, they can surprise you by popping out when you fly by. They roll up and look just like an asteroid, and they unfold when you get to close. Make them slow enough so that anyone who wants to avoid them can with booster, but you better be quick enough or you are dead. I was thinking about having three different sizes [large, gigantic, and Enormous]. The LARGE level monster [the size of the Chitauri Leviathan] can be defeated by at least a single competent level Commander. The GIGANTIC level monster [the size of the Chitauri Leviathan x 4] can be defeat by at least two competent level commanders. The ENORMOUS level monster [the size of the Chitauri Leviathan x 10] can be defeated by at least 3 Master level commanders.