Dilys Derwent

Dilys Derwent was a healer at St Mungo's (1722-1741) and a "celebrated" Headmistress at Hogwarts (1741-1768).

Derwent had long silver ringlets. Her portrait hangs only in Dumbledore's Office along with the postraits of the other headmasters/mistresses, but also in St Mungo's main admitting area. As she can travel between her two portraits, she was able to keep Dumbledore apprised on Arthur Weasley's condition after he was attacked by a snake in 1995.