When he returned, the punch bowl was half empty and all the people, to his delight, were dead. The ice cubes were poisoned. After they melted, the punch became poisoned. I have collected about fifteen more riddles that I can email you. These are tongue twisters sent to the CUNY TESL mailing list.
Students love the challenge.
She saw shy sheep. Rubber baby buggy bumpers. Moses supposes his toeses to be. The Leith police dismisseth us, which causeth us dismay. Round the rugged rock the ragged rascal ran.