The Vampire Diaries, Season 4

Katherine:
I don't think red's really your color, Bon-Bon.

Bonnie:
And here I was hoping the ghost of anyone would have killed you already.

Katherine:
Funny you should mention death because I'm here to collect that immortality you've promised me.

Bonnie:
Funny you think you're still going to get it. I told you, Qetsiyah's the only witch who knows the immortality spell. If she was a no-show, you're out of luck.

Katherine:
See? Here's the thing, Bonnie. I can't disagree with you because I have been feeling out of luck lately, but you know who has been getting all of my luck? My beloved doppelganger, Elena. My shadow self is living a better life than I am, so if I don't get that immortality, I may just have to get rid of her altogether.

Bonnie:
Did you just threaten my best friend? I can crush your skull without even flinching.

Katherine:
Go ahead. Make your move.