Tendril is another of my Marvel-universe mutant concepts. This isn't colored...largely because Tendril is black. Black-black-black. He wears black clothing too, and he's even -darker- in his shadowform (the one on the left), and I didn't feel like trying to come up with fifteen different shades of 'black' while my monitor isn't really behaving. His eyes, however, glow green.
And yes, he sorta looks like some diminutive Darkside-Heartless. It's on purpose.