Joe Manganiello portrayed Marshall’s law school classmate Brad.
“How I Met Your Mother” season 2, episode 5.
CBS
After their girlfriends split up, Brad and Marshall became closer. Ted and Robin ridiculed Marshall for his new bromance in season 2.
Jayma Mays from “Glee” played a club coatroom worker.
“How I Met Your Mother” season 1, episode 5.
CBS
Ted liked her but didn’t exchange phone numbers.
Danica McKellar played Trudy in “The Pineapple Incident”
“How I Met Your Mother” season 1, episode 10.
CBS
Ted spent the show trying to remember things from a drunken night.
Busy Philipps played Rachel, Trudy’s buddy.
“How I Met Your Mother” season 3, episode 3.
CBS
Ted had a threesome with these sorority sisters.
Neil Patrick Harris’ real-life husband played Scooter.
How I Met Your Mother’s David Burtka.
CBS
He was Lily’s high school boyfriend and wanted to win her back.
Amy Acker’s character Penelope helped Ted execute a rain dance.
“How I Met Your Mother” season 1, episode 22: Amy Acker.
CBS
Penelope studied native culture. Ted hoped weather would deter Robin from traveling with Sandy Rivers.
Professor Lewis was played by Jane Seymour.
Jane Seymour on “How I Met Your Mother” season 2, episode 6.
CBS
Marshall thought her divorce made her a tough grader.
“Gotham” actress Morena Baccarin plays Marshall’s crush Chloe.
“How I Met Your Mother” season 2, episode 7.
CBS
Marshall should be careful around Chloe, Barney and Ted advised.
Lucy Hale played Robin’s younger sister, Katie.
“How I Met Your Mother” season 9, episode 19.
CBS
She appears in season 2 and returned for Robin’s wedding in 9.
Ashley Benson was also on “HIMYM.”
“How I Met Your Mother” season 8, episode 14.
CBS
She played Carly, Barney’s half-sister, who briefly dated Ted.
Bryan Cranston was Ted’s unpleasant boss on “Breaking Bad.”
“How I Met Your MotherBryan “‘s Cranston.
CBS
Lily stole one of Hammond’s treasured possessions.
Bob Odenkirk also appeared on “HIMYM” with Cranston.
How I Met Your Mother’s Bob Odenkirk.
CBS
His rough manner gave him the nickname “Artillery Arthur”
Bob Barker was the first game show host to appear on the show.
How I Met Your Mother season 2, episode 20: Bob Barker.
CBS
Barney thought Barker was his dad and confronted him on “The Price Is Right.”
Candice King with red hair on “The Vampire Diaries”
“How I Met Your Mother” season 2, episode 21 featured Candice King.
CBS
She played Lily’s beauty-school cousin Amy. She gave Marshall frosty wedding tips to Lily.
Enrique Iglesias sang as Robin’s Argentine man Gael.
Enrique Iglesias and Cobie Smulders on “How I Met Your Mother”
CBS
MacLaren’s women swooned over him.
Ted was intoxicated with Mandy Moore’s Amy and woke up with a butterfly tattoo.
“How I Met Your Mother” season 3, episode 1.
NBC
Moore mocked Barney throughout the episode.
Because Ted couldn’t remember her name, Abigail Spencer’s character was called “Blahblah”
“How I Met Your Mother” season 3, episode 5.
CBS
She dated Ted online.
John Cho’s character successfully recruited Marshall in season three.
“How I Met Your Mother” season 3, episode 6.
CBS
Marshall left because of the company’s environmental practices.
Heidi Klum was herself in 2007.
Heidi Klum on “How I Met Your Mother” season 3, episode 10.
CBS
Klum gave Barney love advise during a Victoria’s Secret after-party.
Sarah Chalke played Stella, who broke Ted’s heart and left him at the altar.
How I Met Your Mother’s Sarah Chalke.
CBS
Lucy’s mother left Ted for her ex-husband.
Britney Spears played Abby, Ted’s fiancée’s dermatology office receptionist.
Britney Spears on “How I Met Your Mother”
CBS
She dropped her glasses and dressed to get Ted’s attention.
Taran Killam, Smulders’ real-life spouse, guest-starred.
“How I Met Your MotherTaran “‘s Killam.
CBS
Blauman worked in Goliath National Bank’s legal department with Barney and Marshall.
James Van Der Beek played Robin’s first boyfriend Simon as a Canadian adolescent music star.
“How I Met Your Mother” season 3, episode 16.
CBS
Simon and Robin met while filming “Sandcastles in the Sand.”
Alan Thicke from “Growing Pains” as Robin’s former pop star manager.
“How I Met Your Mother” star Alan Thicke.
CBS
He played her father in a music video and on “Space Teens.”
Regis Philbin joined the season 4 burger quest.
“How I Met Your Mother” season 4, episode 2.
CBS
He left “Million Dollar Heads or Tails” to test it.
Kendra Wilkinson posed for a tabloid cover.
In season 4, episode 12, Kendra Wilkinson features on a magazine cover.
CBs
Wilkinson and other reality stars sought to help Marshall conceive.
Spencer Pratt and Heidi Montag mocked Marshall’s bathroom insecurities.
“How I Met Your Mother” season 4, episode 12 featured Spencer Pratt and Heidi Montag on a magazine cover.
CBS
Marshall’s difficulty was short-lived.
Kim Kardashian helped Marshall overcome his bathroom phobia.
“How I Met Your Mother” season 4, episode 12 featured Kim Kardashian on a magazine cover.
CBS
Marshall claimed he didn’t know why Kardashian was famous.
Laura Prepon played Karen, Ted’s snobbish college girlfriend.
How I Met Your Mother’s Laura Prepon.
CBS
Karen’s pretentiousness annoyed Lily and Marshall.
Rachel Bilson played Tracy’s roommate Cindy in “The O.C.”
How I Met Your Mother’s Rachel Bilson.
CBS
Cindy and Ted briefly dated.
Carrie Underwood played Ted’s girlfriend Tiffany.
“How I Met Your Mother” season 5, episode 16.
CBS
Tiffany implored Ted to “be patient” because she didn’t want to lose him.
Jennifer Lopez played Anita in season 5.
“How I Met Your Mother” season 5, episode 17.
CBS
She appeared on “Come On, Get Up New York!” and helped Robin with Barney.
Judy Greer played Royce, one of Ted’s many girlfriends.
Judy Greer on “How I Met Your Mother” season 5, episode 23.
CBS
Ted didn’t like Royce’s favorite movie, “The Wedding Bride.”
Jennifer Morrison was Ted’s enemy-turned-girlfriend on “Once Upon a Time.”
How I Met Your Mother’s Jennifer Morrison.
CBS
She was a NYC activist.
Kyle MacLachlan played The Captain in “Twin Peaks.”
“How I Met Your MotherKyle “‘s MacLachlan.
CBS
Zoey left the Captain for Ted.
Katy Perry was Zoey’s “gullible” cousin in 2011.
Katy Perry on “How I Met Your Mother” season 6, episode 15.
CBS
When Ted and his pals told the story of how they met Perry, they called her “Honey.”
Tim Gunn played Barney’s tailor on “Project Runway.”
“Project Runway” producer Tim Gunn is a mentor.
CBS
He helped Barney with suit emergencies last minute.
“Subway Wars” starred Maury Povich.
“How I Met Your Mother” season 6, episode 4 with Maury Povich.
CBS
Marshall’s coworker mistook Povich and Allen.
Nate Scooberman, nicknamed Scooby, was played by Robbie Amell.
“How I Met Your Mother” season 6 stars Robbie Amell and Cobie Smulders.
CBS
Robin met him in a park after Ted declined her dog request. They broke up quickly.
Will Forte played Barney and Marshall’s coworker Randy Wharmpess.
How I Met Your Mother’s Will Forte.
CBS
Randy quit his job to make beer.
Barney’s father was played by John Lithgow.
How I Met Your Mother’s John Lithgow.
CBS
Reunited after 30 years apart.
Jorge Garcia played Steve “The Blitz” Henry on “Lost”
“How I Met Your Mother” season 6’s Jorge Garcia.
CBS
They met at Wesleyan.
Nicole Scherzinger plays Robin’s ex-best friend.
“How I Met Your Mother” season 6, episode 9: Cobie Smulders and Nicole Scherzinger.
CBS
After Robin had a baby, Glitter and Robin fell apart. Marshall and Lily reconciled them years later.
Alex Trebek from “Jeopardy” hosted a game show.
“How I Met Your Mother” season 6 featured Alex Trebek.
CBS
Robin was the “currency rotation specialist” on “Million Dollar Heads or Tails.”
Martin Short played Honeywell and Cootes senior partner Garrison Cootes.
“How I Met Your Mother” season 7 starred Martin Short.
CBS
Marshall was scared he wouldn’t pass Cootes’ background check because of a streaking video.
Kal Penn played Kevin in “Harold and Kumar.”
“How I Met Your Mother” season 7, episode 4.
CBS
Robin’s therapist/boyfriend was Kevin. Robin’s choice to not have children caused the breakup.
Ted said he inspired “Like a Surgeon” by Weird Al Yankovic.
Weird Al Yankovic on “How I Met Your Mother”
CBS
A singer flashback subsequently verified it.
Katie Holmes played Naomi, Ted’s Halloween party date.
“How I Met Your Mother” star Katie Holmes.
CBS
Ted was disappointed when they lacked chemistry when they reconnected years later.
Rachel Bloom appeared in season seven as a drunk train passenger.
“How I Met Your Mother” season 7, episode 16.
CBS
When Ted approached, she threw him a drink.
Dave Coulier guest-starred on “Full House” in 2013.
“How I Met Your Mother” season 8, episode 15.
CBS
He appeared in a Robin documentary.
Billy Zabka made multiple guest appearances.
“How I Met Your MotherBilly “‘s Zabka.
CBS
Ralph Macchio’s character is popular, but Barney loves Zabka.
Ralph Macchio was himself at Barney’s bachelor celebration.
“How I Met Your Mother” season 8, episode 23: Ralph Macchio.
CBS
Robin pulled this joke.
Keegan-Michael Key and Casey Wilson guest appeared as Calvin and Krirsten.
Keegan-Michael Key and Casey Wilson in season 8, episode 24.
CBS
Robin and Barney plotted to break up the two rival couples. They ultimately up engaged.
Season 9 of “Hamilton” included Lin-Manuel Miranda rapping.
“How I Met Your Mother” season 9, episode 11.
CBS
Gus met Marshall and Marvin on a Farhampton bus.
Tracey Ullman played Robin’s mother in the last season.
“How I Met Your Mother” season 9’s Tracey Ullman.
CBS
Robin was surprised that her flight-phobic mother attended her wedding to Barney.