Bowser junior in a clown car. Made for portrait rooms before a boss, or you can use the ExGFX file for a boss(You'd have to code the boss yourself).
While it's a nice attempt, I'm rejecting this graphic due numeral issues related to shading, size and colors.
First, the shading is inconsistent and lacks a light source. You have to define from where the light is coming from, hence why the clown car and Bowser Jr. looks flat. It also results in a muddiness, making the graphic a bit jarring to look at. Second, the size of the graphic is not great, because it can't be used as boss replacement. Drawing in such small area leaves less room for detailing, so I would suggest, at least to make it 32x32 for the sake of usability. Lastly, it doesn't fit with anything and doesn't resemble the official arts and portrayals of the character. I suggest you to take your time to improve and ask for feedback at SMWC Discord. The channels of #graphic and #help are great places to gather feedback.