In Norse mythology, ravens are very important. Odin, himself, has two messengers that are ravens. Their names are Huginn and Muninn.
This ring represents a raven's skull with some of the most important Viking symbols; namely the Vegvísir and the Valknut.
The Valknut is one of the most widely-discussed yet enigmatic of all of the symbols that appear in connection with Norse mythology and it's associated by many people with the Allfather, Odin.
The Vegvisir, or That Which Shows the Way.This symbol is meant to act as a guide. The Huld manuscript says, “If this sign is carried, one will never lose one’s way in storms or bad weather, even when the way is not known.” As long as this symbol was present, then one would arrive to their destination safely.