Great article from Scientific American... click 'source' to see the whole piece...
1) The Blob
Like many of the X-men, the Blob has gone through several incarnations of character but the one main continuous feature is that he’s big. That’s pretty much it. The size gives him supernatural strength, the ability to be ‘immovable’ (although you could probably shift him with a few tanks if it came to it) and occasionally he has his very own gravitational field. His name is usually Fred Dukes.
The Bacteria: Thiomargarita namibiensis