The Haluu were a race of sentient plants.
When one of their kind, Sythorr, was in favour of overgrowing worlds, eating "fleshlings", and waging war, others believed it was wrong, and Sythorr left his race in a domed escape pod containing a Garden. He created his own Haluu followers by filling his Garden with human "souls". The escape pod hid on Titan for centuries until a ship arrived, but Sythorr's love Oksanna sacrificed herself to destroy the Garden along with Sythorr to atone for her actions.
The Haluu appear to have several biological abilities. Members have been shown to be able to extend their tentacle-like limbs which are fast and strong enough to capture and hold a human and fire from their flower-like ends or mouths spores which put a human to sleep or projectiles that can inflict physical damage on a machine. Being vegetation they are constantly dreaming and therefore able to communicate with other beings across interstellar distances through the "Dreamscape". Members are able to grow wherever their seeds are taken and range in size from being 1-2 ft taller than humans to being dozens of ft tall.
Haluu possess both spacecraft and robots. The escape pod used by Sythorr was a vessel that was hundreds of ft tall and wide, and appeared to be of a conventional design (mechanical and electronics). Maintaining and protecting the garden was a robot, which was willing to use lethal force on intruders. (COMIC: The Soul Garden)