Lindworms

Lindworms are Dragons who live at the roots of the world tree, Yggdrasil.

The Hammer of Thor
Magnus Chase was fighting Lindworms in Hotel Valhalla with Thomas Jefferson Jr., Mallory Keen, Halfborn Gunderson, and new einherji Alex Fierro. However, Grimwold, one of the oldest lindworms, suddenly appears on the battle field. Alex suspects that Loki sent him here and cuts its head off with her garrote while Magnus distracted Grim.

Appearence
Lindworms were the size and lengths of eighteen-wheelers. They only have two front legs and leathery brown bat-type wings.