Mythological beings

[Yex]

I'll echo the sentiment that while it's doubtful that many (if any) mythological creatures exist or have existed on the physical plane, they certain exist as astral and/or spiritual entities, and can thus be interacted with by contacting the appropriate planes (through astral projection, trancework/shamanic journeying, etc).

You use werewolves as an example, though, and I'd like to point out that lycanthropy (the ability to transform into a wolf), and indeed other forms of therianthropy (the ability to transform into an animal) as well, probably have their roots in shamanic shapeshifting magic - although again, this is more readily achieved in trancework than in a literal, physical sense (...although maybe?)

An interesting sidenote is that in 15th-17th century Europe, alongside regular witch trials, there were werewolf trials, where people were accused of lycanthropy. These trials were most prevalent in the Baltic countries - the last area of Europe to be Christianized - where Pagan belief in the ability to shapeshift persisted, and where fear of witches had a decidedly different character than more Christian parts of Europe.