Nice job! You captured both designs really well! The SMB3 model is very sharp!
To be honest, I was always confused by Boom Boom's design in SMB3. I thought he had horns for the longest time. Now that I look at your model, the sprite suddenly makes more sense! Those weren't horns; they were just the eyelids curling. Thank you for clearing up something that's been bugging me for so long!