Quasimodo

Ace made the joke that the figure in a TARDIS mirror "ain't Quasimodo", meaning that he didn't "ring a bell". (PROSE: Echo)

The Seventh Doctor compared the deformed incarnation of the War Chief to Quasimodo, "the Hunchback of the Reich." (PROSE: Timewyrm: Exodus)

Behind the scenes
Quasimodo is the protagonist of by Victor Hugo. In the story, he is the bell-ringer of Notre Dame de Paris.