"He’ll be fine. Murtlap bites aren’t serious."
-- Newt Scamander (WFT)
The Murtlap is a rat-like creature with a growth on its back resembling a sea anemone, which when pickled can be used to promote resistance to curses.
- The Murtlap will attack anyone who steps on it, although it usually eats crustaceans, not people's feet (FB).
- Hermione makes a solution of strained and pickled Murtlap tentacles for Harry who placed his left hand in the bowl and it helps relieve the pain from cutting it open repeatedly in the detention with Umbridge (OP15). This possibly gave protection from future attacks from Umbridge's black detention quill because the Murtlap growth is known to protect against curses and jinxes (FB).
- Harry sees Lee Jordan after his detention with Umbridge with the back of his hand bleeding rather badly and recommends the Murtlap. (OP25)
- Fred says that the boils caused by the prototype Fever Fudge were sorted out by a couple of drops of Murtlap essence and the Skiving Snackboxes were on a roll (OP18, OP26).
- A Murtlap escaped from Newt Scamander's case in 1926 New York, biting a No-Maj named Jacob Kowalski on the neck. He was kept under observation by Newt and the Goldstein sisters, Tina and Queenie, for 48 hours as they waited for the first sign of a severe reaction of "flames from his anus" which thankfully never materialized. Newt did give him some pills for sweating, another side-effect of a Murtlap bite (WFT).
From the Web
"Murtlap" on Harry Potter Wiki