Comment on Toothless Head Diagram by gaernavi

The tentacles are particularly tricky, since they have that point in the middle where they meet (the little red star on the diagram) and the fabric naturally wants crumple up there. I think that is what you are talking about, but please let me know if that isn't the case. What I do to help with those areas is to sew the square-shaped seam on the diagram to give myself more space, and then carefully cut the seam allowance with sharp scissors in that tight corner to loosen up the fabric, taking care not to cut so deep that it reaches your stitch and makes a hole when you turn it right side out.

Another thought is to sew the other DE to C for the other side of the head and see if you get the same result. I hope that helps and please let me know if you have questions Best of luck on your Toothless and I know he/she will come out great!