>>57450711The heart of the problem is that a lot of people's brains short circuit when designing a clown character and they forget basic design principles. They know clowns typically have lots of colors and patterns, so they just do that, without actually thinking about how those patterns and colors work together.
Designing a good clown pokemon should be like designing a good pokemon in general. Give it a cool and/or cute form factor. Pick colors and features that enhance eachother. Avoid unnecessary details that can distract the viewer. You know, the basics.
Ash's dad and Blacephalon aren't the worst, but they both have just unfun body shapes. They look stiff and lanky. Neither the kind of pokemon you want to hug, nor the kind of pokemon you want to see crushing your opponent. Mr mime's colors clash too much, and while Blacephalon's colors are a bit better, the patterns are too intense and busy. The complete lack of a face also isn't winning it any favors.