Academy Award®-nominated actor Don Cheadle (“Avengers: Infinity War,” “House of Lies”) will guest star as Donald Duck’s intelligible voice, as a result of an inventive voicebox, in the epic one-hour season finale of Disney’s hit series “DuckTales,” SATURDAY, AUG. 18 (9:30-10:30 a.m. EDT), on Disney Channel, DisneyNOW, and Disney Channel