S6·E18 Star Witness

When the Ziffels come down with the flu, Arnold the pig stays with the Douglases for a few days, complete with his baggage & ukelele. On a trip into Pixley, Arnold waits in the car, while the Doulases run an errand. Arnold witnesses the Pixley Bank being robbed and notices the robbers description. But with all his squealing he loses his voice, and cannot tell the sheriff what he saw. Mr. Haney tries to sell Mr. Douglas a witness protection service for Arnold. Mr. Kimball tries to track the robbers and ends up giving the real robbers info about where Arnold can be found. The robbers take Eb hostage, thinking he is Arnold. Arnold saves the day by leading the Douglases to the robbers hideout and helping capture them, by pushing a ladder over their heads. Arnold thus collects the $2500 reward.