Slug
When first seeing the cover, I'd genuinely thought it's a book, where Spidey actually faces off against a fellow so big, he makes the Kingpin look skinny. Sadly, when I bought it, opened it up, there was no interaction against, or even with, each other, Spidey may have just only beaten up some of his men. The Slug, operating via phone from a distance, in his palace-like backyard pool, being what I would dig about him.
Ulysses S Lugman. Occupation: Crimelord, Druglord of Miami, Florida. He's a being so obese, that he requires a specialized mobile chair for mobilization, and eat large quantities of food to survive. His base of operations in which he primarily lords in was a palace-like pool area, filled with criminals, women, and drugs, to make the place a hotbed of crime and sins. Loves to party in it too.
Other words, he's a human analogy, of Star Wars' Jabba the Hutt. A buddy of mine, while I pointed out a cover with him while shopping, instantly told me "So he's Jabba the Hutt" before even I ever thought about it. But, yeah, he was.
What absolutely slays me about him, was the manner in which he dispatched those he felt has failed him. He asphyxiates, smothers them to death within the folds of his flesh. Yes, Kingpin was drawn to be pretty "fat" looking, but again and again, he explains it as "all muscle". The Blob, drawn to be pretty fat, even bullets, enemies' punches and kicks been absorbed by his sponginess, but he's got his mutant explanations of controlling his own gravity as well to back him more than just being a fat guy. Slug, well, he's just fat, and he clearly embraces it, with savage, sadistic creativity.
That.Is.Just.Awesome.
He's been more of a Captain America, Nomad, Poison (Miami-based heroine, also happened to be introduced that Web of Spider-Man Annual), and Daredevil, due to the fact he is, after all, also a criminal underworld figure, enemy. Spider-Man appearances of him that I am aware of: Web of Spider-Man Annual #4 (1988), Spider-Man #73-74 (1996).
Current Status, unfortunately: Bankrupt, Imprisoned. Even recent information reveals his great obeseness, in that he is a mutant (boo!, in that he is not just a really, really, fat ordinary human being!).