A symbiote capable of latching on and controlling its host

As a symbiote it was always rather frustrating when you first entered the world, especially ones with more gravity and gaseous atmospheres. It made your already liquid body harder to move when compared to others. If it was a liquid atmosphere you could flow and swim around, or float if it was low gravity but no, it had to like this.

As you slithered out of the ship, you could hear it crumple and collapse into itself, leaving behind a small marble that would borrow into the ground for the time being. That was desirable all things considered, when you precured a host and shelter, you'd come back for it. Now came the more challenging situation, acquiring a host. Your ideal one would be something human, preferably one in its adult stages so you'd have a developed body to use, but you weren't turned of by latching and hiding as an animal or child for the time being.

As luck would have it, soon you heard footsteps approaching your location. There was a potential host in the area, and if what your initial scans on landing in this area was right, it would be alone. You positioned yourself in tree as you heard it moving. All it needed to do was get right under you and that would be it.

The wait didn't take long though as you soon felt its presence underneath the tree. It was time to strike.