Chain Gryffin Done

I have finished the pocket theme (didn't know it'll go that fast). I used mouliné cotton to stitch - they're pretty thick and I hadn't tought they'd be so nice for broidery. I'd like to have a border from several chain lines and the rest will be blue. I don't know how to fill the blue rest - I suppose I'll have to begin from outlining the gryffin but how I'll get to the straight state at the borders - smeg knows... I'm really not sure how to balance this difference :,-(