Klaus is a member of the original family of vampires. He is not only a vampire, but his mother had an affair with someone with a werewolf gene and was impregnated with Klaus, so he is a hybrid vampire-werewolf. He comes to Mystic Falls in an attempt to find Elena, the doppelganger, in order to break the curse that prevents him from turning into a werewolf. When he is successful, he decides he wants to make an army of hybrids and goes on a search for werewolves in attempt to change them. Upon many failed attempts, Klaus finally realizes Elena’s blood is the key to successfully making hybrids. He tries on multiple occassions to drain her of blood or leave town with her, all unsuccessfully. Klaus is eventually staked, however, Bonnie puts a spell on him so he can take over Tyler’s body.

Awww... best line, "and I want to be the last love of your life." I really hope she dies next season and goes over to the Originals.

Yeah... that was definitely the best scene between them so far. I loved it! and I really love Klaus in a weird-twisted sort of way.