September 1988 - Zelda II: The Adventure Of Link
One of the oddest moments in NES side-scrolling sequel Zelda II: The Adventure Of Link is early on in the game where Link enters a house in the town of Ruto and encounters a chap who simply states: "I AM ERROR".
There have been numerous theories on the meaning of this. Some claimed it was a mistake in the game code - that when translating the game over from Japanese the developers forgot to add his name resulting in the game saying "ERROR" instead of his real name.
Others believed it was a mis-translation - due to the fact that the Japanese language doesn't use the letter 'L' - and that his real name was actually Errol, based on swashbuckling action hero Errol Flynn (who played Robin Hood back in the day).
In reality, the result was indeed a translation error, but it wasn't Error's name that was translated wrong. Elsewhere in the game he has a relative called Bagu, who uses the same sprite. It's his name that was translated incorrectly from Japanese - he's actually supposed to be called Bug. Error and Bug, geddt?