He‘d left the garage door open when he took the garbage out, and someone had seen the light come inside. Standing at the side door, he could see a shadow sweep back and forth in the space between the door and the floor, the sound of something rough moving along the wall.
This creature looks like to be a dinosaur (?). It has 2 legs, a torso with a spine and bones, a head with pupils, a nose with no nostrils, and a mouth with lots of teeth. We can't see the rest of its body because its in the darkness as well. It has no skin and is fleshy.