The costume was sort of based on this tutorial (at least the wing template) but the feathers and mask were different. Because lets all pretend that a 21-month-old is going to leave felt goggles on his face, no matter how adorable mom thinks they look.
If anyone actually wants a template for the footies, say so in the comments and I'll make one.
A few notes - the wings were heavy so I put suspenders on underneath his owl shirt and safety-pinned the wings to the suspenders to keep the neck of the shirt from stretching out too much.
I stitched a bit of ribbon to the underside of the wings and then tied it to his arm - this made the wings move with him instead of hanging behind like a cape.
Black girl's leggings made the perfect bottoms.