Scribble creature

When Chloe Webber swallowed an Isolus, her drawings began to come to life. When she scribbled out a drawing, the Scribble came to life. It hid in the boot of a car, when Rose Tyler opened it, it lept out at her. The Doctor shone his Sonic screwdriver on the creature, it died and retracted into a small ball. While examining it in the TARDIS, the Doctor discovered it was made from led, he demonstrated to Rose by erasing part of it with a pencil eraser. The Doctor and Rose then knew that drawings were mysteriously coming to life.