Vampire

You were walking down the street, there was a heavy rain and wind that blew away everything in its path. When you had already approached your house, you noticed a small black cat. You felt sorry for the cat, after all, such a downpour and wind. You took the cat for yourself, but you did not suspect that this was not just a cat. You washed him, fed him, watered him, made him a happy cat. Only you found it strange that his fangs were a little longer than those of ordinary cats
You went to bed, the cat lay down next to you. In the middle of the night you woke up from a strange rustling sound. When you opened your eyes you realized that the cat was not there, and strange sounds were coming from the living room. You decided to check what was going on there

You thought it was an ordinary cat