Terra Sack

Ventriculum Terram or Ground Stomach, commonly known as Terra Sacks (Often misspelt as Terror Sack) are immobile biological horrors that reside deep beneath the ground. They consist of a huge network of stomach and digestive systems and use long tentacles with Lamprey like mouths on the end to catch prey on the surface and swallow them whole where they are digested in the stomach below.

Biology
Terra Sacks are carbon and water based lifeforms, they're especially good at adapting to environments which they are born in. The Terra Sack can be broken down into 2 parts, the Stomach System and the Tentacles. The Stomach System is a large network of multiple stomachs, spread across a large area depending on the size. These break down the victims of the beast whole as the acid is incredibly strong.

Life Cycle
Though observed very rarely, Terra Sacks will eject trillions of spores into the air, equivalent to a small volcanic eruption depending on it's size. These spores will then eventually land on a surface which might come into contact with flora or fauna and begin growing a parasite which attacks animals or trees.

It feeds off of the host's energy and grows exponentially larger, eventually killing the host.

It then grows long fleshy "roots" which search underground for an adequate place to create its vast stomach network.

Terra Sacks will stay dormant for many decades, waiting for enough fauna to flourish on the surface. After some time has passed they grow incredibly long tentacles that connect with the digestive system.

Behaviour
Terra Sacks don't show any form of intelligence and seem to operate on pure animalistic instinct. While the stomach is immobile the tentacles are the ones that do all the work and are the figurative "arms" of the beast.

Tentacles will bury underground, creating long tunnels. They'll then rest just below the surface, looking for vibrations. Once detected, the tentacle will burst out underneath the victim and swallow them whole. Their ability to tell if a vibration is caused by something organic moving does show some amount of basic hunting intelligence.

Document 01
I am ''Dr. Steven Langley PhD leader of a scientific expedition to Tarkin 3 to explore and document potential flora and fauna. I am joined by, Dr. Jessica Wordsworth, Dr. Yad Misra and Dr. Jack Hartmann. We are also joined by 3 security officers lead by Sergeant''

''Initial surface thermal scans pointed us to a heat anomaly in the south-west of the Langley Region (named after myself of course). My colleagues were sceptical at first, suggesting it may be something for the geologists to investigate. I, too, began to believe them, but my curiosity got the better, how unprofessional of me.''

''I have convinced the team to take the shuttle down as there may be more flora and fauna in an area of high heat. They of course were swayed by this and accepted. Our equipment consisted of our planetary survey suits with air filters. Though the planet has a breathable atmosphere, I don't trust any form of pathogens or spores against our primitive biology.''

''We landed the shuttle just outside the anomaly and are beginning the trek through a dense jungle. In fact the closer we reach the anomaly's epicentre, the denser the jungle becomes. Of course, my colleagues were more interested in the local flora, particularly Dr. Jessica Wordsworth, a curious astrobiologist and the youngest of the team. Interestingly enough the local flora was thriving here, more so in the other regions of the planet where life such as this would otherwise not seem to be possible.''

''The 3 security officers that accompanied us weren't the most... intelligent of people, though their child-like appreciation for such a planet is honestly amusing. But for the most part I can honestly see they are bored.''

''"No animals." said one of the security officers, Thusk, they called him.''

''"Pardon?" I asked him.''

''"You see any animals? Everywhere else has animals." He replied.''

''"He's right." Said Dr.Yad Misra, "I've not found any evidence of fauna. And we're in a damn jungle."''

''"None at all?" I asked, doubting my own ability to find life.''

''He sighed, "Bio-Tracker isn't picking up any life forms... except... hold on." He briefly paused as he adjusted the tracker's settings. "The anomaly. No, this can't be right."''

''"I think you might be correct, Doctor." I assured him.''

''We realized the anomaly was too far to travel on foot within the 8-hour day cycle of Tarkin 3, nor did we trust the terrain judging from the orbital scans. We set up a camp at that spot, thankfully no further than 2 miles from the shuttle.''

''Long cave networks that we retraced down to what can only be described as a colossal throat. Thankfully we were unable to smell anything outside the pressure suits because scent readings were more than off the charts, if we could smell we'd probably have passed out. This is evidence that this organism has a preference for meat based diet. We used drones to conduct a safe exploration of the inner network, this fleshy throat like passage lead down to a''