At 25:04 Iolaus tells Typhon "Hercules and I are a team like thunder and lightning, flesh and bone, Abbotus and Costellocles" which references the comedy team of Bud Abbott and Lou Costello.
Echidna and Typhon named their son Obstreperous, which is an adjective meaning "noisy and difficult to control".
At 27:32 Typhon says "Pow! Right in the kisser". This is a tagline from The Honeymooners (1955) which Ralph Kramden used to threaten his wife Alice.
When Echidna retreats further into the cave, she says she is going to "Middle Earth." This series has featured a number of New Zealand actors and filming locations which later appeared in Peter Jackson's Middle Earth movies (Lord of the Rings, The Hobbit).
This is one of Michael Hurst's least favorite episodes.