The best known single narrative involving landvaettir survives in Snorri Sturluson's Heimskringla, recounting how the Danish king Harald Bluetooth, angered at Icelandic poets' insults, sent a wizard in the shape of a whale to scout Iceland's coasts ahead of a planned invasion. At every point the scout attempted to come ashore, he found the land already defended: a dragon accompanied by lesser beasts guarded the north, a huge bird whose wings touched the mountains on either side guarded the east, a bull wading into the sea guarded the west, and a mountain giant carrying an iron staff guarded the south, each landvaettir specific to its own quarter of the island and powerful enough to drive the scout away before he could land.
The story concludes that the invasion was called off once Harald learned Iceland was too well protected by its own spirits to make an attack worthwhile, and later Icelandic heraldic tradition drew directly on this account, adopting the dragon, eagle, bull and giant as the four guardian figures of the national coat of arms, a rare case of a saga era religious belief passing essentially intact into modern civic symbolism. The four creatures' compass positions in the story, dragon north, bird east, bull west, giant south, map directly onto the four field divisions still used in Icelandic heraldry and popular symbolism today, well beyond their original saga context.