Invisibeast

“Invisibeast!” Benny said, coming out with a name for every horrific creature they came across.

"How did it get in here?" V remarked in pale white face.

Although they could not see it, they knew one thing was certain. It was huge. The sound of a large head scraping against the five storey tall corridor, confirmed it. There were more roars as an unseen hand tore down the hall, smashing anything in its path. It was heading right for them.

"Hey ugly, over here," Benny waved his arms wildly, hoping that he could get the attention of this wraithlike fiend.

He began using his powers to lift bits and pieces of rubble, swinging them at the thing. Snorting, the creature now turned its attention to the small boy and lumbered towards him. The only indicator that showed where it was heading was the enormous scratch marks on the floor.