To get Butthole Bob you must beat very hard on classic mode with Jigglypuff 12 times. To get Toad you must shoot all the credits.
If you don't believe me check your game after you get all the people and you will see there is room for 2 more charcter spaces.
PS. after you beat very hard 12 times with Jigglypuff you must turn off the gamecube and turn it back on.
PSS. My friend has seen pictures of when they challenge you.

HAPPY FIGHTING.