I think this article should have a list of all the Pokemon that the Master ball are needed for a the game it is in. Gliscorguy54 21:04, 1 November 2010 (UTC)
WRONG. The Master Ball is NOT needed to catch ANY Pokemon. Ever. I caught Zekrom with full health in an Ultra Ball. -LZ 21:11, 1 November 2010 (UTC)
I had actually caught a Dialga in a normal pokeball so yeah master balls are not needed to catch anything.