Discworld II: Missing Presumed...!?
Normally, using the Suffrajester on Rincewind will have him say "Let's just leave her alone." and do nothing else. However, in the Forest, using the Suffrajester 12 times near the Stones will cause him to change his response to "Not a bad idea, but the legs seem to get in the way." At this point, enter the portal in the Stones, leave and then enter them again. Rincewind will be teleported to a secret room from Discworld featuring the original version of himself and his luggage from that game, where the two will have a humorous conversation about the differences between the games, the incompetency of the players and the developers, the original Rincewind asking for a hint about the first game, and a moment that notably features Discworld II's Rincewind commenting:
"I want to be the first person in a sequel to say f**k! Anyway, nobody wrote in and said they heard it in the first game, it must have been too well hidden! Well who'd have thought eh?"