This episode contains the debut of the character Dr. Bombay.
Bernard Fox (Dr. Bombay) was the penultimate surviving adult recurring cast member of the show, leaving Nancy Kovack (who portrayed character Darrin Stephens' ex-girlfriend Sheila throughout the series) as the only remaining adult cast member upon his death, as of 2019.
Although this is the first appearance of Bernard Fox as Dr. Bombay, the actor had appeared once before in Bewitched (1964), ironically playing a pompous lecturer who didn't believe in witches.
The title refers to the cliche motto of the gold prospector, "There's gold in them thar hills."
When Darrin has a thin voice because of Dr. Bombay's potion, in the Brazilian dubbed version, the tone of his voice is very similar to the voice of the character Woody Woodpecker. This is because Darrin was voiced by the same voice actor who voiced Woody Woodpecker in Brazil, Olney Cazarré (who also voiced numerous cartoon characters using falsetto).