This is the guy that thinks he is stronger than Flashy Flash and Atomic Samurai
Clown Mask
In the webcomic, he fought on par with Black Sperm, and Atomic Samurai called them equal, and said Amai Mask was fit for S-Class. In the middle of his fight with Black Sperm, Evil Natural Water suprise-attacked him, cutting off his arm with a jet of water Child Emperor described as too fast to see. Amai then re-attached it and kept fighting, then Pig God and Atomic Samurai had to double-team Evil Natural Water to buy time for Amai Mask. And then, after Garou dodged out Amai Mask's attack, Atomic Samurai started pleading for his life, going "Noooo, I don't have a weapon, my disciples are unconscious!! We can't do anything!!" And then he took Iain's sword, and got onetapped. Then Amai Mask and Child Emperor came in, and started kicking Garou while Tatsumaki held him still, and he was unaffected, and Garou caved his face in with an attack, giving the real goat of these three, Flashy Flash, his time to shine. He held his own for a couple seconds, and so did Darkshine. Later, Flash got back up, and got taken out with another hit, and Amai, sitting there with his face caved in, was still able to breathe. After the fight was over, Amai Mask stood back up, face in a... fairly intact state, and was able to talk. By the time the heroes had decided to kill Garou, everything but the teeth had grown back.
Monster form is enough of an amp to annihilate that literal clown despite him growing far stronger. Also, Saitama called him cool, but he called Atomic Samurai a "middle-aged weirdo" or whatever