*ahem* Dr. Mad Sciencetein is the top henchmen of the evil clown demon, Rudificus AKA "Rudy." He is your typical mad scientist, with a brain so big he had to add a clear bubble ontop of his head to encase it. He invents potions and formulas, and is very interested in Dr. Mario's special megavitamins.
Dr. Mad Sciencestein first appeared in Warioland 3 in certain levels. Other "clones" of him were made when the citizens of the musicboxland (from WL3) were turned into monsters, but there is one true Mad Sciencestein, whom we saw in Dr. Mario 64. Rudy, who had apparently escaped the musicbox world and entered the Mario world, but lost a significant amount of his power, sent Mad Sciencestein to get Dr. Mario's megavitamins. Mad Sciencestein happily complied, eager to see what made them so potent himself. He got far, but Wario and Dr. Mario stopped him moments before he reached Rudy's castle.
Will we see more of Mad Sciencestein? Who knows! But as you can see, even seemingly simple characters can be made fun and interesting with a little imagination. :)
Hope this helped.
--
I''ve decided to add a signature. Now...what should I type? Hmm...