Who has two hearts?

Answer 1

George Lippert, a sideshow freak who also had a third leg, was born with two hearts. This condition was unknown until the autopsy after his death from tuberculosis at age 62. One of the hearts had actually stopped working several weeks earlier but the other heart was able to sustain him (and would have continued to do so if it were not for the tuberculosis).

See: http://thehumanmarvels.com/?p=62

Answer 2

Yes it is possible, but it will cause death because 2 hearts means too many pumping blood throughout the body. So a doctor can insert 2 hearts into your body, but by the next day, you're dead.

Answer 3

It is a Time Lord, and either call UNIT or Torchwood. Hope this helps!

Answer 4

Nobody