I love that owl! I agree with the above comments.
Several of the tote patterns that I have don't even require hand stitching the openings closed. Instructions are for top stitching by machine all the way around that way the opening is closed up. If I did this, I would be tempted to just stitch the owl without the batting, turn/birth, then cut my batting the same size as the finished owl, then insert the batting, press opening close (tuck under edges) then do the top stitching. That way there won't be any bulk in tiny areas like the ears.