I actually have a VERY fucked up idea for the Doom 4 Spider Mastermind: It's a giant demonic spider (eight legged, not four) with runes all over it, four massive, different coloured eyes, gigantic fangs, and it can kill you in many different ways. The way to defeat this version is to first, shoot out it's eyes, second, shoot it's abdomen, third, shoot out the joints in it's legs using the Railgun, last, climb on top of it and use the BFG to finish it off.