Mordred: My Mother will destroy you!
Brigadier: Just between you and me, Mordred, I'm getting a little tired of hearing about your mother
Brigadier Lethbridge-Stewart: Not this time, Doctor. Armour-Piercing, solid core with a Teflon coating; go through a Dalek.
The Doctor: A non-stick bullet.
Brigadier Lethbridge-Stewart: UNIT's been very busy, Doctor. We've also got high-explosive rounds for Yeti's and very efficient armour-piercing rounds for robots. And we've even got gold-tipped bullets for you-know-what.
The Doctor: No silver?
Brigadier Lethbridge-Stewart: Silver bullets?
The Doctor: Well, you never know...
Brigadier Lethbridge-Stewart: Sergeant, Have we any Silver Bullets?