Fafnir his foster-son Sigurd to kill the dragon. Regin instructed Sigurd to dig a pit in which he could lie in wait under the trail Fáfnir used to get to a stream and there plunge his sword, Gram, into Fafnir's heart as he crawls over the pit to the water. Regin then ran away in fear, leaving Sigurd to the task. As Sigurd dug, Odin appeared in the form of an old man with a long beard, advising the warrior to dig more trenches for the blood of Fafnir to run into, presumably so that Sigurd does not drown in the
Sacred trees and groves in Germanic paganism and mythology abode of gods and spirits. Scholars presume that publicly revered trees such as that at the temple in Uppsala were regarded as counterparts to the mythic world tree Yggdrasil. The present section divides particularly notable examples into texts discussing the religious activities of the ancient Germanic peoples involving trees and groves ("Germanic paganism") and their appearance in the myths of the Germanic peoples, particularly the North Germanic peoples ("Germanic mythology"). Sacred trees and groves are mentioned throughout the history of the ancient Germanic peoples, from their earliest attestations among Roman scribes to references made by medieval monks. In Norse mythology,