1. Old TSR logo (late 70's).
2. TSR, The Game Wizards
3. Wizards of The Coast
4. Harry Potter Mania
5. Unlike a beholder, mind flyer or Meepo the average Joe will actually recognize it.
I vote Dragon, but I think it should be Wormy. Of course, the anti-smoking nazi's would never approve of a cigar-smoking beer-drinking green dragon as the spokesperson for a kids game.