People talk about Pokémon ruined by 3D models like Typhlosion, but I don't think I've seen someone talk about Muk. It looks so weird with its arms flailing around, they way it just bobs up and down, and its derpy look.
Honestly, I think Muk looks cool when it's sprites are done correctly. Take its Gold/Crystal sprites for example:
Or its HeartGold/SoulSilver sprites:
I can't really describe how they makes me feel. Overall, Ijust think that Gen 6+ Muk looks really weird.
Also FireRed/LeafGreen sprite looks kinda funny. Look at his face lol