At 3,000 metres, no sunlight has ever reached. The creatures here have never seen the sky. They evolved their own light — cold, alien, impossible beautiful. They made a world out of pure darkness and they made it glow.
The vampire squid from hell. Neither squid nor octopus. A living fossil that turns itself inside out when threatened, revealing a cloak of luminous spines.
The lure is a bacterial colony, not the fish's own light. It borrowed fire from a microbe and uses it to hunt in eternal darkness. A creature of sublime violence.
Single-celled. Ancient. When disturbed, they flash blue-green. Walk into the sea at night and the water around your legs becomes a galaxy.