Liver

The day started out normally, you were working quietly at home on the computer, but suddenly at some point you felt really bad, and everything started to blur... A couple of minutes later, you woke up on the asphalt in an unfamiliar place.
You stood up and started looking around, after a couple of minutes of thinking, you decided that you should walk forward, maybe to find people.
Having already walked quite a distance, you heard some very loud roar, everything around was so familiar, but so abandoned... The sky was gray-brown, and all the buildings had long been abandoned.
From the direction where the sound came from, you heard moderate stomping and turned towards the sound, and immediately began to back away - some faceless creature was walking towards you. It was all black, covered in some kind of slime, shaking like a phone glitch.
You heard another sound, and the creature turned its head in the direction of the unknown sound. The moment it was distracted, you ran toward an abandoned building, and the creature, having lost track of you, growled loudly and fled into the unknown.
A couple of minutes later, you heard the loud roar of an engine and a rough male voice muttering indistinctly, giving instructions, and you had a choice: go out and ask for help or stay in cover, because who knows what will happen next...