1. Aubrey Plaza as Cat Adams Christopher Polk / Getty Images, CBS Cat, aka the Black Widow Killer, is a psychopathic serial killer and hitwoman who has a keen interest is Dr. Spencer Reid in Seasons 11 and 12. Where you know Aubrey from: Parks and Recreation, Ingrid Goes West, and Legion. 2. Jennifer Love-Hewitt as SSA Kate Callahan Frazer Harrison / Getty Images Kate is a supervisory special agent who joined the BAU during Season 10.Where you know Jennifer from: Ghost Whisperer, Party of Five, and 9-1-1. 3. Jane Lynch as Diana Reid Jamie Mccarthy / Getty Images, CBS Diana is the mother of Dr. Reid. Where you know Jane from: Glee, Two and a Half Men, and The 40-Year-Old Virgin. 4. Cameron Monaghan as Jefferey Charles Michael Kovac / Getty Images, CBS Jeffrey is a child serial killer who appears in the episode "The Boogeyman." Where you know Cameron from: Shameless, Gotham, and Malcolm in the Middle. 5. Forest Whitaker as Sam Cooper Dimitrios Kambouris / Getty Images, CBS Sam is the leader of the BAU's Red Cell team. Where you know Forest from: Phone Booth, The Butler, and Black Panther. 6. James Van Der Beek as Tobias Hankel John Sciulli / Getty Images, CBS Tobias is a delusional serial killer who appeared in the episodes "The Big Game" and "Revelations." Where you know James from: Dawson's Creek, Don't Trust The B**** in Apartment 23, and Varsity Blues. 7. Elle Fanning as Tracy Belle Alberto E. Rodriguez / Getty Images, CBS Tracy is a victim who Jeffrey (Cameron Monaghan) attempted to kill in "The Boogeyman." Where you know Elle from: Maleficent, Teen Spirit, and Super 8. 8. Frankie Muniz as Jonny McHale Frederick M. Brown / Getty Images, CBS Jonny is a vigilante-turned-spree-killer who appeared in the episode "True Night." Where you know Frankie from: Malcolm in the Middle, Big Fat Liar, and Agent Cody Banks. 9. Jason Alexander as Henry Grace Michael Loccisano / Getty Images, CBS Henry was a serial killer who appeared in the episode "Masterpiece."Where you know him from: Pretty Woman, Seinfeld, and The Grinder. 10. Bellamy Young as Beth Clemmons Frederick M. Brown / Getty Images, CBS Beth was the love interest of SSA Aaron Hotchner during Seasons 7 and 8.Where you know Bellamy from: Scandal, Prodigal Son, and A Wrinkle in Time. 11. Gina Torres as Thea Salinas Alberto E. Rodriguez / Getty Images, CBS Thea is a detective who assisted the BAU in the episode "Normal."Where you know Gina from: Suits, Firefly, and Riverdale. 12. Michelle Trachtenberg as Diane Turner Stephen Lovekin / Getty Images, CBS Diane was the stalker and murderer of Dr. Reid's girlfriend who appeared in the episode "Zugzwang." Where you know Michelle from: Gossip Girl, Ice Princess, and Buffy the Vampire Slayer. 13. Mark Hamill as John Curtis Frazer Harrison / Getty Images, CBS John, aka the Replicator, was the infamous copycat serial killer who tormented the BAU throughout Season 8. Where you know Mark from: Star Wars. 14. Amber Stevens West as Joy Struthers Gregg Deguire / Getty Images, CBS Joy is the daughter of SSA David Rossi.Where you know Joy from: Greek, 22 Jump Street, and Fired Up! 15. Aaron Paul as Mike Zizzo Frazer Harrison / Getty Images, CBS Mike was a suspect in the episode "The Popular Kids."Where you know Aaron from: Breaking Bad, BoJack Horseman, and The Path. 16. Mandy Patinkin as SSA Jason Gideon Frazer Harrison / Getty Images SSA Gideon was the head of the BAU during Seasons 1–3. Where you know Mandy from: The Princess Bride, Homeland, and Life Itself. 17. Ben Savage as SSA Jason Gideon (flashback) Rob Kim / Getty Images, CBS Where you know Ben from: Boy Meets World and Girl Meets World. 18. Daryl Sabara as Kevin Rose Alberto E. Rodriguez / Getty Images, CBS Kevin is a young boy involved in child pornography who appeared in the episode "P911."Where you know Daryl from: Spy Kids and Weeds. 19. Tony Todd as Eric Miller Frazer Harrison / Getty Images, CBS Eric is a suspect of the BAU's who appears in the episode "The Fox."Where you know Tony from: Final Destination, Candyman, and Chuck. 20. Jackson Rathbone as Adam Jackson Jason Merritt / Getty Images, CBS Adam is a serial rapist and murderer who appears in the episode "Conflicted."Where you know Jackson from: The Twilight Saga and Finding Carter. 21. Amber Heard as Lila Archer Dimitrios Kambouris / Getty Images, CBS Lila was a love interests of Dr. Reid in Season 1.Where you know Amber from: Never Back Down, Aquaman, and The Danish Girl. 22. Evan Peters as Charlie Hillridge Matt Winkelmeyer / Getty Images, CBS Charlie was abducted as a child and forced into being an unwilling accomplice in the episode "Mosley Lane." Where you know Evan from: American Horror Story, One Tree Hill, and X-Men: Days of Futures Past. 23. Mark Pellegrino as Lieutenant Evans Alberto E. Rodriguez / Getty Images, CBS Lieutenant Evans is a Phoenix-based cop who assists the BAU with a case.Where you know Mark from: Supernatural, 13 Reasons Why, and Lost. 24. Tim Curry as Billy Flynn Kevin Winter, CBS Billy, aka the Prince of Darkness, was a serial killer and rapist from Season 5–6. Where you know Tim from: Rocky Horror Picture Show, It, and The Wild Thornberrys. 25. C. Thomas Howell as George Foyet Alberto E. Rodriguez / Getty Images, CBS George, aka the Reaper, was a prolific serial killer who terrorized the BAU, but specifically Hotch. Where you know C. Thomas from: Southland, Red Dawn, and The Outsiders. 26. Finally, Anton Yelchin as Nathan Harris Pascal Le Segretain / Getty Images, CBS Nathan was a suspect who appeared in the episode "Sex, Birth, Death."Where you know Anton from: Charlie Bartlett, Thoroughbreds, and Star Trek.