Paul the octopus has correctly predicted the winner of all of Germany's matches by choosing between two boxes with the flag of Germany and the flag of its opponent. The chances of this happening by random are extremely low. He has predicted a Spanish victory in the final against the Netherlands.
I have a theory that he just likes the colours red and yellow and has picked the flag with the largest amount of those colours in every case. Germany have more red and yellow in their flag than any country in the matches except Spain, which has more. Spain was the only team to beat Germany and Paul predicted this correctly. Spain, of course, have more red and yellow in their flag than the Netherlands, so that might be why he picked them as winners for the final.
Of course, this theory will fly out of the window as soon as someone tells me that Octopuses can't see colours