In his first form, Marx appears to be a small jester with no legs, arms and hands. He wears brown shoes with small light brown dashes going across them that look like shoelaces. His skin is a light purple/pink color with two big expressive eyes that lie under his hat. His hat is divided into two colors with different shapes on each side. Marx has red with white triangles on the right side and blue with white circles on the left. Marx wears a red bow tie under his small smiling mouth. His beach ball is striped with the colors of his hat: red, white, and blue.
After Marx makes his wish to take control of Popstar, he transforms himself into a fearsome bat-like monstrosity with golden yellow-colored wings with two sharp fang-like claws jutting out from each one. The wings also have flashing mirror-like, multicolored, hexagon-shaped scales under them. Each wing has a red heart on it. His skin retains that purple hue but his eyes are demented looking with big black pupils that face the outer corners. His mouth (which has gotten bigger during his transformation) now has two small fangs in it. Marx's bow tie is noticeably larger, but it appears to be coming undone. Lastly, his shoe color remains the same, but the shoes themselves are longer and are rounded at the ends.
Marx can be Fused with Felix the Cat and Dark Meta Knight