1.First, long before starring in The Haunting of Hill House and Captain Marvel, Mckenna Grace played a younger version of Caroline Forbes. Jean Baptiste Lacroix / WireImage, The CW 2.Chilling Adventures of Sabrina star Jaz Sinclair appeared as Beatrice Bennett, a member of the Bennett coven. Frazer Harrison / Getty Images, The CW 3.Before starring as Kelly Severide in Chicago Fire, Taylor Kinney appeared as Mason Lockwood, Tyler's uncle who was also a werewolf. Jon Kopaloff / FilmMagic, The CW 4.The Walking Dead star Lauren Cohan played Rose, a vampire who was originally on the run from Klaus with her friend Trevor. Frazer Harrison / Getty Images, The CW 5.Long before starring as Oliver Queen on Arrow, Stephen Amell played Brady, a member of Jules' werewolf pack. Jon Kopaloff / Getty Images, The CW 6.Before her music career took off, Hayley Kiyoko guest starred as Megan King, Caroline and Elena's college roommate who was killed by a vampire. Emma Mcintyre / Getty Images, The CW 7.Firefly and Suits star Gina Torres guest-starred as Bree, a witch and one of Lexi's BFFs. Jon Kopaloff / FilmMagic, The CW 8.Before starring on Legends of Tomorrow, Courtney Ford appeared as Vanessa Monroe, a colleague of Alaric's first wife who told everyone about the sun and moon curse. Araya Diaz / WireImage, The CW 9.Teen Wolf and Chicago Fire star Melissa Ponzio appeared as a Mystic Falls citizen who runs into newly turned vampire Logan Fell. Jerod Harris / Getty Images, The CW 10.Before starring on The 100 and American Horror Story, Adina Porter played Nandi LaMarche, a powerful witch from New Orleans. Jc Olivera / Getty Images, The CW 11.Before appearing on Pretty Little Liars, Bianca Lawson guest-starred as Emily Bennett, a super powerful witch who worked for Katherine Pierce. David Livingston / Getty Images, The CW 12.US gymnast Gabby Douglas appeared in Season 4 as a girl who helped Caroline at the Miss Mystic Falls Pageant. Getty Images, The CW 13.The Nanny star Madeline Zima played Charlotte, a vampire Damon sired in New Orleans. Jon Kopaloff / FilmMagic, The CW 14.Drake and Josh and Warehouse 13 star Allison Scagliotti played Georgie Dowling, one of Alaric's interns. Alberto E. Rodriguez / Getty Images, The CW 15.Before starring on The Flash, Rick Cosnett played Dr. Wes Maxfield, a professor at Whitmore College who conducted experiments on vampires. Presley Ann / Getty Images, The CW 16.Before appearing on Pretty Little Liars, Sean Faris played Ben McKittrick, a former Mystic High football star who was turned into a vampire by Anna. Tibrina Hobson / Getty Images, The CW 17.Heroes and Scandal star Jack Coleman played Bill Forbes, Caroline's dad who tortured her because she's a vampire. Paul Archuleta / Getty Images, The CW 18.After starring on The O.C., Melinda Clarke played Kelly Donovan, Matt's estranged mom. Frazer Harrison / Getty Images 19.Sex and the City and Black Lightning star James Remar guest-starred as Giuseppe Salvatore, Damon and Stefan's father. Dominik Bindl / Getty Images, The CW 20.After starring on Eureka, Colin Ferguson played Tripp Cooke, a member of the Fell family and a vampire hunter. Paul Archuleta / Getty Images 21.True Blood star Janina Gavankar appeared as Tessa aka Qetsiyah, the original witch who was in love with Silas. Albert L. Ortega / Getty Images, The CW 22.After starring in 7th Heaven, David Gallagher played Ray Sutton, a werewolf who was turned into one of Klaus' failed hybrids. Frazer Harrison / Getty Images, The CW 23.And finally, Pretty Little Liars and Chicago Med star Torrey DeVitto played Dr. Meredith Fell, who memorably gave her patients vampire blood. Tibrina Hobson / Getty Images, The CW What celebs have you spotted in TVD that you didn't notice the first time? Tell us in the comments below!