When Jason Alexander first signed up to play the title character, he thought he signed up for a one-off role. Because of this, he thought it would be fine to give Duckman a voice very different from his. While he loved doing the show, he reportedly came very close to damaging his voice; and because of this, he didn't reprise his role in the 1997 PC Adventure game.
Well, nice knowing you, son. Not like I don't love you or anything, but you know how people are. They'll assume that sort of thing runs in the family, and frankly I got a tough enough time picking up chicks to begin with. So good luck, be careful, ...
Jack Riley recorded a camo appearance for the episode "Days of Whine and Neuroses" as his Bob Newhart character Elliot Karlin; USA ended up cutting the scene out for time restraints and it has never seen the light of day. A scene was cut from the episode "Aged Heat 2: Women in Heat," in which Duckman violently beats Grandma-Ma, believing her to be Agnes Delarooney, the bank-robbing imposter from season three. USA deemed the scene's content and subject matter "too graphic" for cable TV.