Follow TV Tropes
I've spent years trying to find it, and I just sketched the character in a tumblr post:
As I mention there, the same character mutates from a slug, to a floating human brain, to an intelligent protozoan in the same issue, which may have been a one-shot. It had a human heroine and a futuristic setting.
You need You Know That Show for this question.
Community Showcase More