In The Last Dance, Klaus taught history class at school, while pretending to be Alaric in Alaric's body. He saw Elena, the doppelgänger he needed to break his hybrid curse, and keeps a close eye on her through compelling various students. ... Klaus then awoke in his own body.

What kind of vampire is Alaric?

Alaric is a human, vampire hunter, former history teacher at Mystic Falls High School and a former Enhanced Original, not by being one of the first vampires as the Mikaelson Family is, but instead being turned through an altered version of the spell used on the Mikaelson family.

Who has a doppelgänger in Vampire Diaries?

There are only two doppelgänger "lines" that rippled throughout history, colloquially known as the Salvatore and Petrova doppelgängers. Stefan Salvatore and Tom Avery are Silas' doppelgängers while Tatia, Katerina Petrova and Elena Gilbert are Amara's.