nvm, i just searched about it.. It's called cauliflower ears which is common among wrestlers and fighters...
Hahaha was just about to say they were dumpling ears. But yes, anyone can get them if they get trauma or injury on the ear. I heard there's treatment so they don't stay deformed tho.
they usually don't get it fixed, it's like a trophy to them :D i know a wrestler guy who never had his ear injured so his teammates grabbed to ashtrays and smashed his ear in-between them lol
i have a question about his ears, i thought it's just an error.. But upon looking after a few chapters, his ears are kinda different amongst other characters.. Is that a hidden easter egg?