The Oscuros are a mysterious race of creatures from an alternate dimension. Their skin appears as jet-black, and they don't contain much mass. They appear to be hostile creatures so far, and attempt to steal the Featherwind Pool ship.
They're extremely difficult to kill by normal means. Chris' super urine only makes them stronger, and getting hit by a laser gun only disperses them for a short time, after which they immediately return. They frequently invade the Netherworld via two portals which exist in the Perceptual Boundary. (Perceptual Boundaries)