Vatnavaettir

Vatnavaettir are horses made out of water. Once you touch them you are stuck to them, dragged into the water, and drowned.

Magnus Chase and the Gods of Asgard

While the crew of the Big Banana dock in York, they split into two groups. Magnus Chase, Alex Fierro and Thomas Jefferson Jr. head into town while Samirah al-Abbas, Mallory Keen and Halfborn Gunderson guard the ship from the creatures.

After Magnus defeated Loki in Flyting, the crew escaped using one of the Vatnavaettir Sam actually befriended.

Magnus Chase and the Gods of Asgard
Core Series:	The Sword of Summer \| The Hammer of Thor \| The Ship of the Dead
Main Characters:	Magnus Chase \| Alex Fierro \| Blitzen \| Halfborn Gunderson \| Hearthstone \| Loki \| Mallory Keen \| Samirah al-Abbas \| Sumarbrander \| Thomas Jefferson Jr.
Secondary Characters:	Randolph Chase \| Gunilla \| Natalie Chase \| Amir Fadlan \| Alderman
Minor Characters:	Annabeth Chase \| Frederick Chase \| Helgi \| Hunding \| Vala \| Junior \| Lars Alhstrom \| Inge \| Percy Jackson \| Stan \| Alviss \| Miles \| Wildflower \| Sunspot \| John Henry
Norse Gods:	Freya \| Thor \| Balder \| Ullr \| Frey \| Odin \| Heimdall \| Vidar \| Sif \| Frigg \| Tyr
Minor Gods:	Skírnir \| Mimir \| Ran \| Hel \| Sigyn \| Aegir \| Nine Billow Maidens \| Njord \| Kvasir \| Holler \| Snotra \| Forseti \| Glum \| Lofn
Jotnar:	Surt \| Gerd \| Norns \| Utgard-Loki \| Harald \| Ymir \| Geirrod \| Gjalp \| Greip \| Thrym \| Thrynga \| Tiny \| Little Billy \| Hrungnir \| Red \| Tattoo \| Gunlod \| Suttung \| Baugi \| Skadi \| Hrym \| Eggther \| Norns
Monsters:	Jormungand \| Ratatosk \| Vedrfolnir \| Nidhogg \| Fenris Wolf \| Lindworm \| Wight \| Brunnmigi \| Siersgrunnr \| Garm
Magical Creatures:	Dwarf \| Elf \| Sleipnir \| Stanley \| Marvin \| Otis \| Hulder \| Nøkks \| Vatnavaettir \| Nisser \| Troll \| Raven \| Hugin and Munin
Related Content:	Rick Riordan \| Hotel Valhalla Guide to the Norse Worlds \| 9 from the Nine Worlds