Enemy ideas that will make you bulk detonate yourself
Starting off strong we have the cave leech ball, which is a mix of a shellback with a cave leech. Rolls around and leaves a cave leech where it goes occasionally.
Next is, what if there were variations of ghosts, instead of always being a bulk detonator? Heres probably the worst one you could think of; ghost mactera grabber! (Can be detered by being shot for balancing purposes)
Finally, saving the worst for last, a mactera/glyphid hybrid species, and one of them is a bulk/goo bomber hybrid! :D