Question: Joseph Morgan is best known for his roll in what CW show that eventually spun off into "The Originals"?

full_context: Document 1: Estries: Estries are female vampires of Jewish folklore that were believed to prey on Hebrew citizens, particularly men. The name derives from the French "strix", a term for a night owl. In some accounts they are considered identical with succubi: both were portrayed as beautiful, blood-thirsty female demons, with Succubi thought to favor babies and young children as prey. Estries, like other vampires, needed to feed on blood to survive and were more indiscriminate in their choice of victims. Succubi were said to kill pregnant women and babies out of jealousy or spite, and to seduce (or in some cases rape) men. Estries and succubi were both said to be able to appear as humans or in spirit form at will, but Estries were also described as able to turn into birds or cats and various other animals.
Document 2: Colin Morgan: Colin Morgan (born 1 January, 1986) is a British/Irish film, television, theatre and radio actor best known for playing the title character in the BBC fantasy series "Merlin", the lead in "The Living and the Dead", and main roles in "Humans" and "The Fall"; his stage role as Ariel in "The Tempest"; and film roles in "Testament of Youth", "Legend" and "".
Document 3: You're Undead to Me: "You're Undead to Me" is the fifth episode of the first season of The CW television series, "The Vampire Diaries" and the fifth episode of the series overall. It originally aired on October 8, 2009. The episode was written by Sean Reycraft and Gabrielle Stanton and directed by Kevin Bray.
Document 4: List of The Originals characters: "The Originals" is an American fantasy-drama television series picked up by The CW for their fall 2013 schedule, after a backdoor pilot for the series aired as an episode of The CW television series "The Vampire Diaries" in April 2013. It is a spin-off of "The Vampire Diaries", sharing a universe with its predecessor. It centers on three Mikaelson siblings, Klaus (Joseph Morgan), Elijah (Daniel Gillies), and Rebekah (Claire Holt), collectively known as "original vampires", or simply the "originals". "The Originals" is set in the city of New Orleans. It was created by Julie Plec.
Document 5: Ian Somerhalder: Ian Joseph Somerhalder (born December 8, 1978) is an American actor, model and director. He is known for playing Boone Carlyle in the TV drama "Lost" and Damon Salvatore in The CW's supernatural drama "The Vampire Diaries".
Document 6: Joseph Morgan (actor): Joseph Morgan (born Joseph Martin; 16 May 1981) is an English actor and director. He is best known for his role as Klaus Mikaelson in The CW show "The Vampire Diaries" and its spin-off "The Originals".
Document 7: Count Dracula: Count Dracula is the title character of Bram Stoker's 1897 gothic horror novel "Dracula". He is considered to be both the prototypical and the archetypal vampire in subsequent works of fiction. He is also depicted in the novel to be the origin of werewolf legends. Some aspects of the character are believed to have been inspired by the 15th-century Wallachian Prince Vlad III the Impaler, who was also known as Dracula. Other character aspects have been added or altered in subsequent popular fictional works. The character has subsequently appeared frequently in popular culture, from films to animated media to breakfast cereals.
Document 8: Founder's Day (The Vampire Diaries): "Founder's Day" is the 22nd episode of the first season of The CW television series, "The Vampire Diaries" and the 22nd episode of the series overall. It also consists the last episode of the season. It originally aired on May 13, 2010. The episode was written by Bryan Oh and Andrew Chambliss and directed by Marcos Siega.
Document 9: The Vampire Diaries (season 2): The Vampire Diaries, a 40 minute American supernatural drama, was officially renewed by The CW for a full 22-episode season on February 16, 2010. The first episode premiered on September 9, 2010, at 8 p.m. ET. The season picks up immediately after the events of the season one finale. All the series regulars returned. Season two focuses on the return of Elena Gilbert's (Nina Dobrev) doppelgänger, Katherine Pierce, the introduction of werewolves, the sun and moon curse, and the arrival of the original vampires. Tyler Lockwood's (Michael Trevino) uncle, Mason Lockwood (Taylor Kinney), arrives in town searching for the moonstone, a family heirloom. Tyler later learns of his family's werewolf curse. Meanwhile, Caroline Forbes (Candice Accola) is killed by Katherine while having Damon Salvatore's (Ian Somerhalder) blood in her system, turning her into a vampire. The arrival of the original vampires, Elijah (Daniel Gillies) and Klaus Mikaelson (Joseph Morgan), also bring about complications. Klaus is a vampire-werewolf hybrid, but his werewolf side had been forced into dormancy by witches, as nature would not stand for such an imbalance in power. Therefore, Klaus arrives in town with plans to break the curse and unleash his werewolf side by channelling the power of the full moon into the moonstone, sacrificing a vampire and a werewolf, and drinking the blood of the doppelgänger. The season is currently on air in Urdu on filmax channel in Pakistan. It became available on DVD and Blu-ray on August 30, 2011.
Document 10: Jason Momoa: Joseph Jason Namakaeha Momoa (born August 1, 1979) is an American actor, model, director, writer, and producer. He is known for his television roles as Ronon Dex on the military science fiction television series "Stargate Atlantis" (2004–2009) and as Khal Drogo in the HBO fantasy television series "Game of Thrones" (2011–2012).
Document 11: Damon Salvatore: Damon Salvatore is a fictional character in The Vampire Diaries novel series. He is portrayed by Ian Somerhalder in the television series. Initially, Damon is the main antagonist in the beginning of the show and later became a protagonist. After the first few episodes, Damon begins working alongside his younger brother, Stefan Salvatore, to resist greater threats and gradually Elena begins to consider him a friend. In 1864, Damon became a vampire after being shot by his father with Katherine's blood in his system. His transition was completed after his younger brother Stefan, who is also a vampire, convinces him to drink blood. Damon, angry that Katherine chose to turn Stefan as well, vows to make his brother's life sorrowful – thus further causing a century-long rift between the two brothers. Elena Gilbert chooses to be with Damon in the finale episode.
Document 12: Michael Raynor (actor): Michael Raynor, is an American actor, director and writer. His best known roles are as Joseph Morgan in "ER (TV series)", Apollo 15 Astronaut Al Worden in "From the Earth to the Moon", Mick in the movie "A Brother's Kiss" and Frank in the movie "Federal Hill."
Document 13: Old Ones (Buffy the Vampire Slayer): In the Buffyverse, the Old Ones are the extremely powerful, pure-breed demons that once dominated Earth before humankind appeared. Illyria is one of these demons (though its real form was revealed only in an illustration) while it's more than likely that Jasmine and her kind (The Powers That Be) ascended to their higher plane because of the growing malevolence of these warring demons. It's also possible that the Powers that Be were part of the same race but shared a different philosophy than the other Old Ones.
Document 14: Original Vampires (The Vampire Diaries): The Original vampires, in the universe of "The Vampire Diaries" and "The Originals", are a family of vampires from which all current vampires descend, as well as being the most powerful and indestructible of their kind. In Autumn 1001 AD, after the death of her youngest son Henrik at the hands of werewolves, the powerful witch Esther performed an occult blood ritual in order to protect her five remaining children—(Finn, Elijah, Niklaus, Kol, and Rebekah)—and her husband, Mikael. The ritual transformed her family into the first vampires.
Document 15: The Vampire Diaries (season 3): "The Vampire Diaries", a one-hour American supernatural drama, was officially renewed for a third season by The CW on April 26, 2011, that aired from September 15, 2011, to May 10, 2012. The third season consisted of 22 episodes and focused on the story of Klaus' origin, his relation with his family and reveal more about the original family. The third season opened to generally positive reviews. The season takes a gap from the last season and begins with Elena Gilbert's 18th birthday with all series regulars returning with the exception of Sara Canning whose character Jenna Sommers was killed off in the previous season. Joseph Morgan's character Klaus became a series regular instead of returning as a recurring character.
ground_truth: The Vampire Diaries