Some guy responsible for editing fighter profiles/updating records did that for a good laugh I'm sure. Because Ive yet to hear Manny referred to as "The Greatest" anywhere else.
That's the boxrec dudes I'm sure. It actually says, "The Greatest Light Welterweight ever" or some **** like that. Very silly and good way to make boxrec look even less professional. http://www.boxrec.com/search.php?status=all&cat=boxer&first_name=manny&last_name=pacquaio&submit=Go
The only nicknames I know that MP has used in his career were "the Destroyer" (late 90's or early 2000s) and "Pacman" (2003-present)
Yeah he is the greatest of today without a doubt,mayweather might be able to beat him but his accomplishments sure rank him as the greatest of our era.