The embryonic lifeform was the name given to an energy creature from the Gamma Quadrant by Starfleet. The species start their life in a crystalline form. Vash discovered what she thought was a crystal made of Promethean quartz during her time in the Gamma Quadrant with Q. When Vash was found by the crew of the USS Ganges, she was brought to Deep Space 9. The energy creature caused a power drain on the runabout, and when Vash and Quark held an auction, did the same on Deep Space 9. Benjamin Sisko and his crew were able to identify that the crystal was the cause before the station was destroyed and transported the crystal into space, where it changed form and entered the Bajoran wormhole, returning to the Gamma Quadrant. (DS9 episode: "Q-Less")