3. The Lone Surviving Dalek Was Going To Be Tortured
The Creature You Know: Originally not intended to make any appearance in the revived series, the Daleks soon became an essential part of Nu-Who (to the extent their episodes began to get eye rolls from fans), but their very first appearance in the revived series seemed ready to wipe them from the face of Skaro (and, of course, Earth). Purporting to show us the only Dalek to survive the Time War, the succinctly titled Dalek gave us a mutated soldier now prisoner to a greedy collector, chained up and weakened. But originally things were much more tortuous.
The Early Design You Dont: The general design of the new gold Daleks came about pretty easily - it's just a sturdier version of the classic enemy - but what went through many stages was this particular Dalek. The script originally seemed to play up the devious side of man (a theme rightfully sidelined to allow the true villain to give maximum terror); the concept art above has the cyborg not only tied up, but with its insides being experimented on. I imagine budgetary reasons stopped this version coming to fruition, but given the shock of seeing the mutant Kaled as the end of the episode, its a worthwhile compromise.