"....and he chose one from among the whelps of the race of Draugluin; and he fed him with his own hand upon living flesh, and put his power upon him."

I can go both ways with this, but I'm still going to say it was Morgoth's own flesh 'cus that's just cooler

QUESTION: How did Maedhros and Maglor know that their right of claim over the Silmarils had been voided due to their violent actions?