Actress Kat Graham; comic Greg Proops.

Olympic figure skater Tara Lipinski; comic Keegan-Michael Key.

Actor Verne Troyer; guest comic Nyima Funk.

Actor Darren Criss; guest comics Jeff Davis and Greg Proops.

Actor Michael Weatherly; guest comic Greg Proops.

Sumo wrestler Byambajav Ulambayar; guest comic Gary Anthony Williams.

Actor Nolan Gould; guest comics Jeff Davis and Greg Proops.

Actress Mircea Monroe; guest comic Gary Anthony Williams.

Guest comic Keegan-Michael Key.

TV personality Jack Osbourne; guest comic Nyima Funk.

Professional football player Rob Gronkowski; guest comic Jonathan Mangum.

Actor Robbie Amell; guest comic Jeff Davis.

Actor Misha Collins; guest comic Brad Sherwood.

TV host Sheryl Underwood; guest comic Jeff Davis.

Singer Mel B.; comic Gary Anthony Williams.

Actor Kunal Nayyar; comic Brad Sherwood.

Comic Jeff Davis.

Chef Padma Lakshmi; guest comic Heather Anne Campbell.

Guest comic Jeff Davis.

Professional basketball player Matt Barnes; comic Gary Anthony Williams.

Guest comic Gary Anthony Williams.

Weightlifter Brian Shaw, the “World's Strongest Man”; comedian Heather Anne Campbell.

Wendi McLendon-Covey; comedian Jonathan Mangum.

Comedian Heather Anne Campbell.

Cedric the Entertainer; guest comic Gary Anthony Williams.

Actress Adelaide Kane; guest comic Jeff Davis.

Guest comic Keegan-Michael Key.

Actor Jaime Camil; guest comic Jeff Davis.

Actor Scott Porter; guest comic Greg Proops.

Reality-TV star Willie Robertson ("Duck Dynasty"); guest comic Jeff Davis.

Actress Heather Morris; guest comic Brad Sherwood.

San Francisco 49er Vernon Davis; guest comedian Keegan-Michael Key.

Guest comic Jeff Davis.

Illusionists and entertainers Penn & Teller; guest comedian Gary Anthony Williams.

TV host Kathie Lee Gifford; guest comedian Brad Sherwood.

Retired mixed martial artist Randy Couture; guest comedian Jonathan Mangum.

Guests: Actress Gina Rodriguez and comedian Jeff Davis. Games played: Weird Newscasters, Duet, Themed Restaurant, Scenes from a Hat, and Helping Hands.

Guest: Comedian Gary Anthony Williams. Games played: World's Worst, Whose Line, Irish Drinking Song, Props, Doo Wop, and Greatest Hits.

Guests: Supermodel Nina Agdal and comedian Heather Anne Campbell. Games played: World's Worst, Song Styles, Dead Bodies, Scenes from a Hat, and Helping Hands.

Guest: Comedian Brad Sherwood. Games played: Let's Make a Date, Props, Secret, Scenes from a Hat, and Greatest Hits.

Guests: Science guy Bill Nye and comedian Greg Proops. Games played: Weird Newscasters, Newsflash, Song Styles, Scenes from a Hat, and Helping Hands.

Guest: Comedian Keegan-Michael Key. Games played: Hollywood Director, Scenes from a Hat, Whose Line, Hats/Dating Service Video, and Greatest Hits.

Guests: TV host Carson Kressley and comedian Heather Anne Campbell.

Guest: Comedian Jeff Davis Games played: Scenes from a Hat, Whose Line, Forward Rewind, Newsflash, and Greatest Hits.

Guests: comedian Gary Anthony Williams; actor Alfonso Ribeiro.

Guest: comedian Keegan-Michael Key.

Guests: comedian Jeff Davis; actor Karla Souza.

Guests: comedian Gary Anthony Williams; actress Yvette Nicole Brown. Games Performed: Hollywood director, duet, scenes from a hat and helping hands

Guests: comedian Jonathan Mangum; actress Kaitlin Doubleday Games Performed: Let's make a date, duet, dubbing, scenes from a hat and helping hands

Guest: comedian Jeff Davis.

Guest: comedian Jonathan Mangum.

Joey Fatone; comedian Jeff Davis.

Tamera Mowry-Housley; comedian Greg Proops

With guest star appearance by comedian Jeff Davis.

With guest star appearance by May-Treanor.

With guest star appearance by Lyndie Greenwood.

With guest star appearance by Chris Jericho.

With guest star appearance by Rachel Bloom.

Actress Lea Thompson; comedian Jonathan Mangum.

Actress Katie Cassidy; comedian Brad Sherwood.

Guests: comedian Jeff Davis and actor Brett Dier.

Guests: comedian Gary Anthony Williams and actress Emily Bett Rickards.

Guests: comedian Jonathan Mangum.

Guests: comedians Brad Sherwood and Jeff Davis, plus actress Cheryl Hines. Games played: Let's Make a Date, Doo Wop, Duet, Scenes from a Hat, and Helping Hands.

Guest comics Tony Hawk and Heather Anne Campbell.

Guests: comedian Jeff Davis, plus actress Candice Patton. Games performed: Let's make a Date, World's Worst, Living Scenery, Props, Scenes from a Hat, Hoedown

Guests: comedian Gary Anthony Williams, plus actor Malcolm Goodwin.

Guests: guest comic Gary Anthony Williams, plus actor Wil Wheaton.

Guests: comic Jonathan Mangum, plus actor Kearran Giovanni.

Guest: comedian Brad Sherwood.

Actor Ralph Macchio; guest comic Jonathan Mangum.

Guests: comic Greg Proops, plus actor Tony Cavalero.

Guests: comedian Heather Ann Campbell, plus celebrity trainer Jillian Michaels.

Guests: comic Jeff Davis, plus actor Charles Esten.

Musician Wanya Morris; guest comic Jonathan Mangum.

Guest Danielle Panabaker; guest comic Gary Anthony Williams.

Actress Marisol Nichols; guest comic Jonathan Mangum.

Actress Grace Byers; guest comic Brad Sherwood.

Guests: comedian Greg Proops, plus TV personality Ross Matthews. Games played: Weird Newscasters, Song Styles, Themed Restaurant, Scenes from a Hat, Living Scenery.

Jeff Davis guests on the improvisational-comedy showcase in which the performers wing it unscripted and unrehearsed.

Guests: comedian Gary Anthony Williams, plus actress Andrea Navedo.

Jonathan Mangum guests on the improvisational-comedy showcase in which the performers wing it unscripted and unrehearsed.

Charles Esten and Jeff Davis guest on the improvisational-comedy showcase in which the performers wing it unscripted and unrehearsed.

Greg Proops guests on the improvisational-comedy showcase in which the performers wing it unscripted and unrehearsed.

Jonathan Mangum guests on the improvisational-comedy showcase in which the performers wing it unscripted and unrehearsed.

Keegan-Michael Key guests on the improvisational-comedy showcase in which the performers wing it unscripted and unrehearsed.

Heather Anne Campbell guests on the improvisational-comedy showcase in which the performers wing it unscripted and unrehearsed.

Guest comic Gary Anthony Williams.

Carmen Electra guests on the improvisational-comedy showcase in which the performers wing it unscripted and unrehearsed.

Guest: comedian Jeff Davis. Games performed: Let's Make a Date, Irish Drinking Song, Sound Effects, Props, Greatest Hits.

Guest: comedian Greg Proops. Games performed: Questions (With Hats), Props, Whose Line, Scenes from a Hat, Party Quirks, Doo-Wop.

Guests: comedian Jeff Davis and actor Cornelius Smith Jr. Games performed: Weird Newscaster, Duet, Living Scenery, Scenes from a Hat, Helping Hands.

Guest: comedian Gary Anthony Williams. Games performed: Questions (With Hats), Sound Effects (With Audience Members), Film Dub, Scenes from a Hat, Greatest Hits.

Guests: comedian Greg Proops and singer Lance Bass. Games performed: Let's Make a Date, Song Styles (with an audience member), Mixed Messages, Scenes from a Hat, Helping Hands.

Guests: comic Charles Esten and TV host Chris Hardwick. Games performed: Questions (with Hats), Moving People, Song Styles, Scenes from a Hat, Helping Hands.

Guests: comedian Jeff Davis and singer-songwriter Tinashe.

Guest: comedian Jonathan Mangum

Guest comic Brad Sherwood.

Guests: comedian Gary Anthony Williams and Olympian Adam Rippon. Games performed: Dating App, Mixed Messages, Song Styles, World’s Worst, Living Scenery, Scenes from a Hat.

Guest: comic Heather Anne Campbell. Games performed: Let’s Make a Date, Newsflash, Whose Line, Scenes from a Hat, Greatest Hits.

Guests: comedian Jonathan Mangum and actor Chris Jackson.

Guest: comedian Jeff Davis.

Guests: comic Greg Proops and talk show host Adrienne Houghton.

Guest: comic Brad Sherwood.

Guest: comic Jonathan Mangum.

Guest star appearance by Amber Riley.

guest comedian Greg Proops

Four members of the regular cast, accompanied by guest stars, perform various comic games and sketches.

Four members of the regular cast, accompanied by guest stars, perform various comic games and sketches.

guest comedian Jonathan Mangum

Guest: comedian Jeff Davis. Games played: Weird Newscasters, Hoedown, Infomercial, Scenes from a Hat, Greatest Hits.

Guest: comedian Gary Anthony Williams.

Guest: comedian Jonathan Mangum.

Guest: comedian Greg Proops.

Guest: comedian Nyima Funk.

Guest: comedian Greg Proops.

Guest: comedian Heather Anne Campbell.

Guest: comedian Jonathan Mangum

Guest: comedian Jeff Davis

Guest: comedian Gary Anthony Williams

Actor Kevin McHale; guest comic Heather Anne Campbell.

Boxing champion Laila Ali; guest comic Jeff Davis.

Guest comic Keegan-Michael Key.

Guest comic Heather Anne Campbell.

Guest comic Nyima Funk; Olympian Shawn Johnson.

Guest comic Greg Proops.

guest comedian Keegan-Michael Key

guest comedian Jonathan Mangum

guest comedian Jeff Davis

Guest star appearance by Kyle Richards ("The Real Housewives of Beverly Hills")

Hosted by comedian Aisha Tyler, cast members Ryan Stiles, Wayne Brady and Colin Mochrie, along with guest comedian Jonathan Mangum, put their comedic skills to the test.

Hosted by comedian Aisha Tyler, cast members Ryan Stiles, Wayne Brady and Colin Mochrie, along with guest comedian Heather Ann Campbell, put their comedic skills to the test. Guest star, Padma Lakshmi

Hosted by comedian Aisha Tyler, cast members Ryan Stiles, Wayne Brady and Colin Mochrie, along with guest comedian Darren Criss, put their comedic skills to the test.

Hosted by comedian Aisha Tyler, cast members Ryan Stiles, Wayne Brady and Colin Mochrie, along with guest comedian Gary Anthony Williams, put their comedic skills to the test.

Hosted by comedian Aisha Tyler, cast members Ryan Stiles, Wayne Brady and Colin Mochrie, along with guest comedian Jeff Davis, put their comedic skills to the test.

Guest comic Gary Anthony Williams.

Hosted by comedian Aisha Tyler, cast members Ryan Stiles, Wayne Brady and Colin Mochrie, along with guest comedian Brad Sherwood, put their comedic skills to the test.

Four performers must use the little information they have and their wild imaginations to depict different characters and an array of scenes, as well as perform songs.

Guest comic Gary Anthony Williams.

Guest comics Brad Sherwood and Jeff Davis.

Special episode featuring a compilation of games, moments, and outtakes of never-before-seen footage.

A special episode featuring a compilation of games, moments, and outtakes of never-before-seen footage.

Guest comedian Rachel Bloom.

Guest comic Jack Osbourne.

A special episode featuring a compilation of games, moments and outtakes of never-before-seen footage.

Guest comic Mircea Monroe.

Guest comic Kat Graham

Guest Greg Proops joins the cast for a series of spontaneous improv games that are prompted only by random ideas supplied by the studio audience.