Suggestions by @acthepantherno1

Keith David

as Apollo Creed in Rocky (1986)

Mary Elizabeth Mastrantonio

as Adrian in Rocky (1986)

50 Cent

as Ferris in Boyz n the Hood (2001)

André 3000

as Dooky in Boyz n the Hood (2001)

Big Boi

as Monster in Boyz n the Hood (2001)

Stan Shaw

as Officer Coffey in Boyz n the Hood (2001)

Ice Cube

as Producer in Boyz n the Hood (2001)

Stanley Clarke

as Composer in Boyz n the Hood (2001)

De'Angelo Wilson

as Chris "Lil' Chris" Brown in Boyz n the Hood (2001)

Paul Winfield

as The Old Man in Boyz n the Hood (2001)

Aunjanue Ellis-Taylor

as Reva Devereaux in Boyz n the Hood (2001)

Tichina Arnold

as Brenda Baker in Boyz n the Hood (2001)

Meagan Good

as Shalika in Boyz n the Hood (2001)

Tatyana Ali

as Shanice in Boyz n the Hood (2001)

Bianca Lawson

as Brandi Harris in Boyz n the Hood (2001)

Ludacris

as Darin "Doughboy" Baker in Boyz n the Hood (2001)

Tyrese Gibson

as Ricky Baker in Boyz n the Hood (2001)

Wesley Jonathan

as Tre Styles in Boyz n the Hood (2001)

Terrence Howard

as Jason "Furious" Styles in Boyz n the Hood (2001)

John Singleton

as Director in Boyz n the Hood (2001)