Gullinbursti

Gullinbursti (Old Norse: [ˈɡulːenˌburste], meaning "Golden Mane" or "Golden Bristles") is a boar in Norse mythology.

When Loki had the sons of Ivaldi craft Sif's hair, Freyr's ship Skíðblaðnir, and Odin's spear Gungnir, he wagered his own head with Brokkr that Brokkr's brother Eitri (Sindri) could not forge items of equal quality to the aforementioned treasures.

To create a gift for Freyr, Eitri placed a pig’s hide into a furnace while Brokkr worked the bellows. Together, they forged the boar Gullinbursti, which had bristles in its mane that glowed in the dark.

The story of Gullinbursti's creation is told in the Skáldskaparmál section of the Prose Edda by Snorri Sturluson.

Then Sindri placed a pigskin in the forge and instructed Brokkr to pump the bellows without stopping until he had taken the item out of the forge. When Sindri left the smithy and Brokkr continued to pump, a fly landed on his hand and bit him. Nevertheless, Brokkr continued pumping as before until the smith retrieved the work from the forge. It was a boar with a mane and bristles made of gold. ... Brokkr then presented his gifts. ... He gave the boar to Freyr, explaining that it could run faster through air and water than any horse, and it could never become so dark at night or in the shadowy realms that there would not be sufficient light where the boar went, as its mane and bristles shone brightly.

According to Húsdrápa, Freyr rode on Gullinbursti to Baldr's funeral, while Snorri's Gylfaginning states that Freyr travelled to the funeral in a chariot pulled by the boar.

The boar is also known as Slíðrugtanni (Old Norse: "Sharp Tooth" or "Terrifying Tooth"), sometimes Anglicised as "Slidrugtanni."

In Folklore

In a Dutch folktale, a fairy prince named Fro, son of Nerthus, creates the golden-bristled boar, named Gullin in the story, using gold.