Silent (The Daft Dimension 482)
From Tardis Wiki, the free Doctor Who reference
In the Daft Dimension, a Silent once snuck onboard the Doctor's TARDIS alongside a Cyberman, Dalek and Zarbi. However, the Doctor forced them to reveal themselves by scraping his nails on his blackboard, producing a sound which all four monsters found unbearable. (COMIC: The Daft Dimension 482)
