He wears a long, dark robe with white sleeves and the Delta Rune on the front, with a large collar and shoulder pads.
This form is not named directly in the movie, where the 'Check' option labels Shadow as 'the absolute GOD of Hyperdeath!' The sclerae of his eyes become black, his fangs become longer, and he becomes white. He also has a large pair of quills on the back of his head. In his initial form, he wears a green, long-sleeved shirt with yellow stripes and black pants, similar to the First Human's clothing. Different to Fluttershy and Asgore, Shadow has short ears, a snout, and visible fangs.