The fountain that Fergus is dumped in in the opening scene is the "Friend's Fountain" from the opening of Friends (1994)). The fountain has undergone various transitions over the decades. This version had a pond where Fergus landed, three dragon serpents and a fountain with a mini pond on top.
A previous episode revolved around Samantha's successful attempt to get a bank loan to tear down the gazebo in her backyard. In this episode, when Fergus shows up in the Stephens' backyard, the gazebo is still there, and is even mentioned by Darrin.
When Darrin and Samantha exit out the front door with Phebe and Ferguson, it is only the first time they exit the front door on the sound stage, not the house on the Columbia Ranch.