The Neoshadow is a Pureblood Heartless introduced in Kingdom Hearts Final Mix.
Kingdom Hearts 358/2 Days
After returning to the World That Never Was in order to reclaim Kingdom Hearts and revitalize Xion, Roxas is attacked by several Neoshadows. He eliminates them, but is forced to side with Riku in order to finish off the rest of the continuously spawning Heartless. As soon as the Heartless are taken care of, however, the two Keyblade wielders turn on each other.
A Neoshadow has a more humanoid body structure than a normal Shadow, but shares the same pitch black skin and spherical, glowing yellow eyes. Its crooked antennae are quite long and fall back behind the Heartless. It seems to be rather muscular, and its hands are very large, each one sporting five clawed fingers. Its feet, like those of a normal Shadow, are long and lack digits, but a Neoshadow’s feet more resemble boots. Its body is also lined by several faint, blue veins of color.