User blog comment:Adventuretimegenghiskhan/Is Finn the only human?/@comment-4532735-20111120205111

Jake is Finn's brother. That's all the relatives and family he needs. :) Also, I am pretty sure that mutants and "pure humans" (like Finn & Fionna, and possibly also Susan Strong) can have babies with mutants. Characters like Marceline, Princess Bubblegum, and of course the tribe of Susan Strong, are all humanonoids. They are also all made out of flesh and blood (unless, PB, who's made out of sugar). So the population HUMANOIDS may grow, but the HUMAN population will probably die out after one or two generations, because then all humanoids will be mixed with mutants and vampires and wizards. :) There COULD be some more humans left, somewhere. The earth is really big, after all. We haven't seen everything yet.