Black Dog in the Hallway at Grandmother's House

When I was little, I often went to sleep over at my grandma's. And one night I wanted to get up and go to the kitchen to drink some water. I'd just thrown off the blanket when I realized that some weird fucking shit seemed to be going on, I peered into the doorway, the hallway was completely dark. And then after a while, as if from the floor, a black dog rises up, huge, taller than a German shepherd. I fucking freaked out big time, stayed on the couch hiding under the blanket, and fell asleep like that. In the morning I told my grandma what had happened at night, she made a surprised face and then said that it must be that during the construction of the house someone got badly hurt or hit themselves, after those words it got really scary. By the way, my grandma didn't have any dogs, or any other animals either