Alien- Flat Wall

  The sound starts above us, a low, growling click that makes the hairs on the back of my neck stand on end and my skin get tight as every primordial instinct I have left screams, screams, screams for me to run, to get to cover, to get away.
...

  The creature doesn’t move. It doesn’t seem to care about how much effort it should take for something of its size to sit on a flat, vertical surface like the wall: it just crouches, perfectly balanced, preparing to strike.
...

  And then she turns and runs, hands in the air, screaming with all the force she can find. She runs, and the creature … it doesn’t run after her. “Run” implies that it ever touches the ground. It leaps, a single terrible, graceful moment, and hits her from behind. Then it leaps again, and there isn’t even time for her to scream. In an instant, she’s gone.

Echo, Chapter 11