The fleinsopp (liberty cap) mushroom is a psilocybin "magic" mushroom that contains the psychoactive compounds psilocybin, psilocin and baeocystin. The Vikings dried it, and used itas an hallucinogenic drug. Typical symptoms associated with ingestion: spontaneous laughter and delirium. 
The Ottastafur rune was used during war and combat. It means; to put fear into the enemy.
The Vikings wore the Trollkors (Troll cross) for protection and good luck. Worn by travelers as an iron amulet to ward of black magic and evil spirits.