Draco's eyes widened as the creature fell from the ceiling, but it had hit the floor before Draco's Arresto Momentum was even halfway recited. He winced at the crash, but advanced slowly, wand extended.

"Well now." He crouched, still a good five feet away, examining the body closely, keeping a careful watch for signs of it becoming a little too mobile again. He wished he could cast Finite Incantatem, see if it changed shape, but that would undo the charm holding it in place. "What exactly are you?" he asked idly as he Transfigured a scrap of paper into a small vial and levitated a smear of venom from the thing's claws. This might help him find out.