Darkgnaw

 The Darkgnaw is a Keychain for Terra's Keyblade that appears in Kingdom Hearts Birth by Sleep.

Design
The Darkgnaw's shaft has a deep-grey edge which curves in at intervals, the inside fading from dark red to black from its base, which has several angled lines pointing toward the guard as the center bears a bright red line, stretching to the tip as it leads to an equally red rune marking. The teeth are axe-like, with the same coloration as the top of the shaft, an angled piece and several lines cut out, giving the illusion of teeth. The guard is a dark steel blue and has a hexagonal shape with numerous semicircles imprinted around it. The hilt is plain black. The Keychain bears a strong resemblance to the one on Master Xehanort's Keyblade.

The Darkgnaw's name, as well as its Japanese name, "Dark Biter", refer to the Keyblade's teeth, which resemble an actual toothed maw. "Dark" simply reflects the dark design of the Keyblade.