Hippocrates Smethwyck was a healer at St Mungo's Hospital for Magical Maladies and Injuries. He was the healer-in-charge of the 'Dangerous' Dai Llewellyn Ward. He found the antidote for whatever the snake's fangs had in them which healed Arthur Weasleys wounds from his snake attack (which was assumed to be Lord Voldemort possessing his snake, Nagini).
The name "Hippocrates" is the Latinized form of the Greek name ‘Ιπποκρατης (Hippokrates) which meant "horse power", derived from the elements ‘ιππος (hippos) "horse" and κρατος (kratos) "power". This was the name of a 5th-century BC Greek doctor who is known as the Father of Medicine.