Your dragon looks to be made of crochet cotton. When I've made things that need stiffening, I've used white elmer's glue. I would suggest crocheting each spike, then laying it on aluminum foil or plastic wrap and soaking each spike with white glue and press the spike out with your fingers to get it into the shape you need. Let it dry then attach it to your dragon. It really does work a treat. Keep in mind that a dragon's spikes will no all stand up perfectly straight. So you may want to make some with a bit of tilt or bend for character. Hope this helps.