The Vampire Diaries, Season 5

Silas:
Oh. I'm outing myself as not-Stefan. Obviously. Don't be afraid. Don't move.

Sheriff:
What's happening?

Silas:
We've met before, actually, when I was appearing as your daughter. To bash your head in? Does that ring any bells?

Sheriff:
Silas.

Silas:
Indeed. I am a 2,000- year-old immortal that Caroline and her friends thought they got rid of.

Sheriff:
Are you appearing to me as Stefan?

Silas:
Well, yes and no. This is my true form. Stefan is my doppelganger.