Basement Beast

You hear the small bumping nose coming from down stairs, so you go and investigate. As you heading in the basement you notice it smells like wet dog. This is actually the first time you've been down here but when you go to turn on the lights the don't come on. You call out to see if anyone is down there with you but no one answers. The basement has only a small window only big enough to fit your hand though, but the rest of the basement seems too be empty besides the large box at the far corner of the room.

You hear the bumping again and something wet hits the floor coming from where the box. So you go to see what's inside. Once you get closer to the box you see that its actually a cage and there's a large creature inside. You suddenly slip on something wet and hear a click and a growl. You jump back to your bare feet to see the cage door slowly opening. Scared of what might come out you back away from the corner.

A large creatures pushes the cage door open and starts walking toward you. You make it to the stairs and turn around as fast as you can and run up the stairs, but something grabs you by your ankles and pulls you down the stairs. You panic and peak over your shoulder and see?