User blog comment:Skeith9/Heroic Spirits Speculation/@comment-82.141.107.33-20170925103405/@comment-88.115.164.91-20170925133413

Judging by the Berserker card's hands and feet, its not so much a minotaur as a person wearing the head of a beast. Perhaps someone with ties to some sort of pagan/occult figure (Baphomet, for example?). Since Berserkers have to have been or said to have been mad at some point in their lives, I suppose from the point of view of Christian Europe a pagan would've been pretty nutty.

As for Rider, one might note the fact that that many Servants wearing plate armor are from waaaay before plate armor was a thing. So it could be just some knightly (by conduct, ie. honourable and so on) Heroic Spirit known for riding a chariot from a much earlier era.

Archer might be some kind of Amazon? They were famous archers, as I recall.