Vortex

The Vortex are the antagonists of the first two Ecco The Dolphin games on the Sega Genesis console. They originate from a planet in the Cassandra system in the Pegasus constellation.

Description and Biology
The Vortex are large, cephalopod-like creatures with green skin and large, oblong, bulbous heads. They have four grasping arms and a central tentacle. The queen resembles the drones, but is much larger, far larger than the bottlenose dolphin who defeated her, and more aggressive.

There are also warrior drones, which are heavier and armored in comparison to the worker drones. They are brown in color with two arms that each end in a pair of long, sharp claws, and they have a long, stinger tail.

Vortex larvae are round, translucent creatures with three long, flexible limbs extending from them. They slightly resemble Earth jellyfish.

The Vortex are an always hungry, predatory species. Every 400 years, the Vortex feed off Earth's oceans when the two planets align. They are intelligent and sentient, seemingly with some knowledge of technology and biological modification. They fought several wars during Earth's history with the people of Atlantis, eventually destroying the civilization and forcing them to escape into the past with their technology.

History
When the Vortex sucked up the pod of a dolphin named Ecco, he battled his way through Earth's oceans and into a machine that could take him to the Vortex world. There, he battled the drones and eventually the vortex queen, freeing his pod and returning them to Earth. However, the Vortex queen had not died, and she followed the pod back to Earth, deciding she would try to take it over.

Ecco's previous battle had messed up the time stream, and the Vortex created a dark future which Ecco had to work to prevent. He managed to defeat most of them in the present, and the queen and a few followers escaped into the past. However, they were unable to dominate Earth's ancient oceans, and were no longer a threat after Ecco destroyed the Atlantean machine. It is indicated that the Vortex evolved into what we know today as arthropods.