In Clue, the Singing Telegram Girl (Jane Wiedlin) is a character who visits Mr. Boddy’s party to deliver a message, before being killed by one of the guests. She is later revealed to be a former patient and lover of Professor Plum’s.

In Clue, Professor Plum (Christopher Lloyd) is a former psychiatry professor with the World Health Organization who had his license revoked after having an affair with a female patient. He is a guest of Mr. Boddy’s and is being blackmailed for his indiscretions. In one of the endings, he killed Mr. Boddy in the hall with the candlestick.

Miss Scarlet (Lesley Ann Warren) is a character from the board game, Clue. In the film adaptation, she is a socialite who runs an illegal escort service, for which she is being blackmailed by Mr. Boddy. In one of the ends, she killed the cop in the library with a lead pipe.

In the film, Clue, Mrs. Peacock (Eileen Brennan) is the high society wife of a Senator. She is a guest of Mr. Boddy’s party, and is being blackmailed for accepting bribes to deliver her husband’s vote. To stay true to the board game, Mrs. Peacock killed the cook in the kitchen with the knife.

In Clue, Colonel Mustard (Martin Mull) is a guest of Mr. Boddy’s who’s being blackmailed for war profiteering. It’s revealed that he made his money from selling stolen radios on the black market, as well as having an affair with one of Miss Scarlet’s escorts. In one of the endings, he killed a stranded motorist in the lounge with a wrench.

In Clue, Mrs. White (Madeline Kahn) is a “black widow” who had her husbands disappear or die mysteriously. She is a guest of Mr. Boddy’s, and is also being blackmailed by him. The maid had an affair with one of her husbands, so in one of the endings, she killed the maid in the billiard room with a rope.