T'Keyah 'Crystal' Keymáh

T'Keyah Crystal Keymáh (born Crystal Walker October 13, 1962) is an American performer, writer, director, and producer. In addition to her status as an original cast member of the Fox sketch comedy series In Living Color, she is perhaps best known for her roles as Erica Lucas on the CBS sitcom Cosby, and as Tanya Baxter on the Disney Channel sitcom That's So Raven.