The fish that chew dead skin off a persons feet are called Garra Rufa fish where people put their feet into a tank of the Garra Rufa fish and allow the fish to eat the dead skin of their feet which is also known as a fish pedicure.
The Garra Rufa fish are A variety of Turkish toothless carp fish.
It's not advised by dermatologists though to allow those fish to eat the skin off your feet even though it has been shown to be beneficial to some people.