Quote from FMPONEVikings were not fucking around at all. A lot of times they would take psychedelic mushrooms before combat
fun fact: i've read that scandinavians in more northern parts used to have their reindeer eat amanita muscaria, so they then could drink the piss of that reindeer. the idea was that the reindeer would filter out all the toxins because they're more resistant to it.
it's a bit weird that they (vikings) would bother to use muscaria when it's mostly a deliriant and produces a much less lucid state than the even more available psilocybe semilanceata (which they also used). perhaps the analgesia made it easier for them to berserk. and perhaps the believable hallucinations made them think they really were at the gate of asgard participating in the most epic battle ever. there's really no limits to the suggestibility of delirium... (or psychedelics for that matter)
i'm hoping we will see some of it in the series. the introduction scene where he hallucinates valkyries was pretty cool.