Pretty sure this may be one of Onyxia's eggs. I'm an avid fan of the Warcraft Dragon's and all of their lore. I have a theory about the spiky eggs since everyone's first comment is 'OUCH!' When first laid I think the eggs are smooth, but later develop spikes as a defense to predators, as if the mother wasn't enough of a deterrent!

Cast in durable resin from my sculpted original. Available in my Etsy store https://www.etsy.com/shop/TheDragonsHorde