Zard

Zards are reptiles one to two feet long with eight legs, each tipped with tiny grasping claws as sharp as their teeth. Tough membranes between the legs form gliding wings on both flanks, giving them easy, nimble flight. Coloring stays in the blue-green range, from forest green to pale blue, sometimes mottled or striped. Ages of drifting have withered their eyes, so they are effectively blind.

Zards are too dim to be malicious, though swarm attacks have been blamed on angry gods in several star systems. A swarm hunts by sonar: it lets out a shrill, far-carrying squeal and steers toward whatever returns the echo, predator or prey alike, which keeps their numbers down. It follows a target to impact, then scatters as each zard clamps on and starts eating, at 1-2 damage per bite. The claws are too small to hurt anyone. Once landed, zards are slow and easy to kill, but they breathe air: every five use as much as one human, straining a ship's air envelope.

Most zards live in the void between worlds, nearer planets where fresh air is easier to get, and they steal it from whatever they attack. Traveling swarms of up to 100 cling together leg to leg and move in a rippling wave, like a dolphin's undulation. In the rarer flame-sea swarms glide its glowing currents, but they turn to stone once their air is spent, drifting petrified until they hit a ship or object with air, which revives them at once for a feeding frenzy.

With plenty to eat, a swarm drifts peacefully, mating and birthing on the wing. Newborns are hungry immediately and can eat solid food. Zards eat wood, rope, paper, flesh, bone and even thin metal. After a few weeks of scarcity they may turn cannibal, and whole swarms have destroyed themselves that way.

Void scavengers of every kind hunt zard swarms for meat, and many have been devoured instead. Hippo-headed mercenaries and gazer tyrants relish the taste too, so starship-faring systems trade zard meat briskly. The teeth and claws make fine pen nibs, and web-eel slavers are said to use the creatures when interrogating prisoners.