His eyes also change color in this form, gaining red sclerae and lighter green irises, and his quills are more bushy and ended in white tips. His third and most iconic form was a crystalline, anthropomorphic hedgehog with no mouth, nose or even feet, instead his legs ended in a purplish mist. Just like Shadow, he had rings on his wrists and ankles. In his second form, Mephiles appeared almost identical to Shadow the Hedgehog, aside from having green eyes with slit pupils, a pale-skinned muzzle with no mouth (though his muzzle moves when he speaks, as if he does have one), and the fact that everything that is red on Shadow is a greyish-blue on Mephiles.

His original form was an amorphous mass of darkness, which emitted an aura and behaved similarly to liquid.