Question: A water dragon in England known as a peg powler is similar to a water spirit connected to the monster in 'Beowul' called what?

Context paragraphs:
Each-uisge: The each-uisge (] , literally "water horse") is a mythological Scottish water spirit, called the each-uisce (anglicized as "aughisky" or "ech-ushkya") in Ireland.  It is similar to the kelpie, but far more vicious.

Physignathus: Physignathus is a genus of large, diurnal, arboreal, agamid lizards, commonly known as water dragons.  The two species are the Chinese water dragon "P. cocincinus", and the Australian water dragon "P. lesueurii".  They are sometimes kept as pets, especially "P. cocincinus".  Its generic name is Greek for "inflated jaw".

Ogopogo: In Canadian folklore, Ogopogo or Naitaka (Salish: "n'ha-a-itk" , "lake demon") is a lake monster reported to live in Okanagan Lake, in British Columbia, Canada.  Ogopogo has been allegedly seen by First Nations people since the 19th century.  The most common description of Ogopogo is a 40 to 50-foot-long (40 to ) sea serpent resembling an extinct Basilosaurus or Mosasaurus.  Skeptic Benjamin Radford notes that “these First Nations stories were not referring to a literal lake monster like Ogopogo, but instead to a legendary water spirit.”

Australian water dragon: The Australian water dragon ("Intellagama lesueurii", formerly "Physignathus lesueurii" ), which includes the eastern water dragon ("I. l. lesueurii" ) and the Gippsland water dragon ("I. l. howittii" ) subspecies, is an arboreal agamid species native to eastern Australia from Victoria northwards to Queensland.  There may be a small introduced population on the south-east coast of South Australia.

Peg Powler: The Peg Poowler, otherwise known as 'Peggy Powler the nice nan', is a dragon from English folklore with red scales, short hair and big teeth who is said to inhabit the River Tees.  It bites the ankles of those who wander too close to the water's edge, especially nice children, and pulls them under the water and drowns them; in Middleton In Teesdale this is referred to as the High Green ghost.  It is highly similar to the Dutch folklore figure Haantje Pik, the Slavic water spirit Vodyanoy, Kalle met de Haak from West-Flanders and the German water spirit Hastrman.  Grindylows and Jenny Greenteeth are similar water spirits.

Chinese water dragon: Chinese water dragon ("Physignathus cocincinus") is a species of agamid lizard native to China and mainland Southeast Asia.  It is also known as Asian water dragon, Thai water dragon, and green water dragon.

Grindylow: A grindylow or grundylow is a folkloric creature that originated from folktales in the English counties of Yorkshire and Lancashire.  The name is thought to be connected to Grendel, a name or term used in "Beowulf" and in many Old English charters where it is seen in connection with meres, bogs and lakes.

Wangliang: Wangliang (魍魎 or 罔两) is the name of a malevolent spirit in Chinese mythology and folklore.  This word inclusively means "demons; monsters; specters; goblins; ghosts; devils" in Modern Standard Chinese, but "wangliang" originally meant a specific demon.  Interpretations include a wilderness spirit like the "kui" 夔 "one-legged mountain demon", a water spirit like the "long" 龍 "dragon", a fever demon like the "yu" 魊 "poisonous 3-legged turtle that causes malaria", a graveyard ghost also called wangxiang 罔象 or fangliang 方良 "earth demon that eats the livers or brains of corpses", and a man-eating "demon that resembles a 3-year-old brown child with red eyes, long ears, and beautiful hair".

Jenny Greenteeth: Jenny Greenteeth is a figure in English folklore.  A river hag, similar to Peg Powler or a grindylow, she would pull children or the elderly into the water and drown them.  The name is also used to describe pondweed or duckweed, which can form a continuous mat over the surface of a small body of water, making it misleading and potentially treacherous, especially to unwary children.  With this meaning the name is common around Liverpool and southwest Lancashire.

Nuckro Water: Nuckro Water is a loch of southeastern Whalsay, Shetland Islands, Scotland.  It is located to the east of the Loch of Stanefield, northwest of Treawick and southwest of Isbister, passes by the main road on its eastern side.  Also known as Nuckra, Nyker, or Nyuggle, the name comes from the water spirit said to haunt lonely places.  There is a disused quarry just to the northeast and the remains of a prehistoric house nearby.  On the southeastern side, across the road near the source of Falsa Burn is an unroofed building, which was probably used as a mill; it was shown on the 1st OS map of Orkney and Shetland in 1882.  In the southeastern corner of the loch there are stepping stones across the water.

Supporting paragraphs: Peg Powler Grindylow
Answer: Grindylow