Can you promote a pawn to a second king?


He needs to checkmate the two kings which is very hard
fischer done it in 1976 and won by time because his opponent couldn't checkmate the 2 kings at same time

No, the rules state that a pawn reaching the 8th rank must be exchanged for a bishop, knight, rook, or queen. No king.
Edit: Damn troll thread.

Try playing Knightmare chess, there are few cards that allow having 2 kings. While player has 2 kings he can leave one of them in check and even captured but once he has only 1 king it has to be checkmated

Everything about this subject has been said there :
http://www.chess-poster.com/english/mail/mail_2012/promotion.htm
Featuring Capablanca, a flying saucer, the end of the world, and two kings promotions.