I just went ahead and drew my interpretation of the Bart sprite seen in the Acclaim Simpsons games on NES (Bart vs. the Space Mutants, Bart vs. The World, and Bart meets Radioactive Man), clearly from the time when the NES was losing it's relevance thanks to the Super NES and Genesis being out at the time.

What you're seeing is the sprite, plus my best recreation of how Bart looked in the show's classic era and my interpretation of how the sprite looks to me.