In the first part of the Shahnameh, "The Shahs of Old", the Deev-influenced king Zohak has a dream in which he foresees his own downfall at the hands of Feridoun and his cow-headed mace:
Zohak dreamed he beheld a youth slender like to a cypress, and he came towards him bearing a cow-headed mace, and with it he struck Zohak to the ground. Then the tyrant awoke and trembled, and called for his Mubids, that they should interpret to him this dream. And they were troubled, for they foresaw danger, and he menaced them if they foretold him evil. And they were silent for fear three days, but on the fourth one who had courage spake and said-
"There will arise one named Feridoun, who shall inherit thy throne and reverse thy fortunes, and strike thee down with a cow-headed mace."
How could the Mubids tell that the youth's name should be Feridoun? I'm guessing this would make more sense in Persian: perhaps the word "Feridoun" is similar to one meaning "cypress" or "slender", or another word used in the description of the youth in the dream. The Wikipedia page mentions the etymology of the name, but is not helpful in constructing any connection with this dream.