The Fish I Have Are a bicolor blenny, a lawnmower blenny, a mandarin, a yellow tang and blue hippo tang a clown fish and a royal gramma but if it was fin rot wouldn't the other fish get it???
Clowns are nippers, but it could also be a disease of some sort. Just because one fish has symptoms of a disease doesn't mean all the other fish in your tank have to be showing symptoms too. Some fish are hardier than others and are just not as affected by diseases.