Fanghur or "Wind-vipers" as they were called, were cousins to the Dragons of Alagaesia native to the Beor Mountains. They were adorned with leathery wings similar to those of dragons, but were smaller, could not breathe fire, and were less intelligent than dragons. They had dappled green or brown scales for camouflage.
Fanghur stunned their prey with an immobilizing mental screech and then killed them once the victim was subdued. They usually hunted in packs of three or four. Dragons and Fanghur are distant cousins, but are less closely related to them than Dragons were to Nïdhwal.
Fanghur were extremely endangered during Eragon and Saphira's time. When traveling from the city of Tarnag to the Âz Ragni River, Eragon and Saphira were attacked by a group of three Fanghur, but thanks to Saphira's strength and her fire-breathing, the Fanghur were scared away, with one being injured in the fight. Arya commented that they would be sorely missed if Saphira had killed them, implying there were very few Fanghur left. The Dwarf clan known as the Dûrgrimst Fanghur (led by Grimstborith Havard at the time of the novels) were named after them.