17 Abner Come Home | The Sewer King

Abner Come Home: Abner, Arnold's beloved pet pig, sees a cat out the window and he runs out of the boarding house to chase it, which leads to him running far away from home. The next morning, Arnold wakes up to realize that Abner is gone. Later, he announces a search party so everyone can help find Abner before something bad happens to him.
The Sewer King: While Arnold goes out to bring Grandpa his golden watch back from the store, he sees a gigantic hole being dug for new sewer pipes at a construction site. As he looks down it, the watch falls out of his pocket and into the sewer. Now, Arnold and Gerald must go down there to retrieve it, only to find that it's in possession of the Sewer King.