Question: in what episode of vampire diaries do the originals appear?
Answer: The birth of Klaus brought back hope to Mikael, and Klaus was followed by Kol, Rebekah, and Henrik. Klaus first appears in The Vampire Diaries season 2 episode 17 titled "Know Thy Enemy" possessing Alaric's body. Klaus first appears in his own body on The Vampire Diaries in season 2 episode 19 titled "Klaus".