Fridge Monster

The creature takes the form of a small, dark greenish-black blob with no fixed shape. It oozes across floors, walls, and ceilings with surprising speed, reshaping its body as it slithers along. Its origin is a Ganymede rock lobster that Spike bought in 2070 and left forgotten in the ship's attic, where it festered into the thing over the following year.

The blob's chief threat is its bite, which pumps a toxin into whatever it sinks into. Victims break out in a purple rash and lose consciousness, though the story never confirms whether the venom can actually kill. Paired with its speed and its knack for flowing into any shape, the toxin makes the creature a slippery, dangerous quarry in the ship's cramped spaces.

The monster strikes first at Jet, Faye, and Ein, dropping all three with its rash-inducing bite and leaving Spike as the last one standing. He arms himself with a heat sensor, nets, and gas grenades to hunt it down, but rather than killing it he ends up shoving the entire fridge out into space, and the creature ambushes him and knocks him out at the final moment. The thing meets its end almost by accident: it slinks up to a dreaming Ed, who mistakes it for a sweet bean roll, called pudding in the English dub, and swallows it whole. Whether the poison harmed Ed is left open, though Spike had set the autopilot for Mars in case she too was laid low.