Not a cat

I was 17 years old then. I went to bed as usual, and my cat, Murza, lay down, as usual, on my lap. The door to the room, as always, was closed, and I slept without a light. The light from the street lamp illuminated the entire room perfectly. And then, in the middle of the night, I woke up to the door creaking halfway open. Half asleep, I immediately gave myself the all-clear, thinking the cat had jumped off the bed and opened the door with its paw to get out. He did that often.

And just as I was about to fall asleep, I suddenly heard an unpleasant sound, as if the cat was slowly sharpening its claws on the other side of the door. I took a deep breath to shush the cat (I was completely stunned – he wouldn't let me sleep), and then I heard a purr. It turned out the cat was on the bed! His back was arched, his fur was standing on end, his tail tucked between his legs, staring at the door.  And the door would slowly close, then halfway open—and someone was scratching behind it, no longer hiding at all. I was speechless. I could only feel goosebumps all over my body and the hair on my head standing on end with terror. The door was heavy; even the cat had difficulty opening it, often asking for help. But here it was, moving smoothly but creakingly back and forth. That meant something bigger than the cat was hiding behind it...

Everything was unfolding very quickly, but it seemed like an eternity to me then. I realized that any moment now the door would open all the way. And sure enough—the door suddenly froze (the cat hissed and darted off into a corner of the room with a yelp) and abruptly swung open completely. I screamed at the top of my lungs, "Mom-a-a!" and covered my face with my hands to avoid looking at what was hiding behind the door.

My parents ran into the room. My mother tried to calm me down until the morning.  I was truly hysterical. Even now, I can't recall that horrific incident without shuddering. Incidentally, my blanket was found under the bed, neatly folded into a sort of roll...