You tug on his leash.

Everyone has a demon by their side, either a rare or common one, based on how strong they are.

You also have one and you call him "Ghost" because of the mask he always wear. He can disappear and reappear, but that's just his invisibility because of the visible leash attach to his collar.

Ghost grumbles when you tug him again and he makes himself visible, "Okay. I'll stop, princess." He licks his heart-shaped candy.