Starro

Starro is a large starfish-like creature that was frozen for millennia.

Early life
Atlantean scientists led by Vulko found the creature, and started examining it in the Atlantean Science Center in Poseidonis.

Present
The attack on Poseidonis was led by Black Manta on behalf of the Light, primarily to steal the creature from the Science Center. The plan was thwarted by Aqualad and Garth. Black Manta blew up the creature with a missile, but a piece survived the blast and began regenerating. Prince Orm decided that it would be best that the piece be taken to the surface world for further studies, considering the fact the Science Center had been greatly damaged and could not safeguard the piece.

The Light stated that they would acquire the regenerating piece of Starro at a later date for an unknown plan.

While Klarion and his band of sorcerors had split the world into two dimensions, one for adults and one for children, Lawrence Crock led a mob of angry and confused parents to the STAR Labs facility in Gotham, demanding answers. This distraction gave Riddler a chance to sneak into the facility and steal the echinoderm sample.

Riddler and Sportsmaster later presented the tentacle to the Brain and the rest of The Light.