Original title: "The Chrysalis A-B-C". This was the only Season Two episode in which Tony Anholt doesn't appear, a result of having been filmed simultaneously with Catacombs of the Moon (1976) (18 June to 6 July 1976, Nick Tate turning 34 on the first day of shooting, then Martin Landau turning 48 on the third day of shooting). According to Tate, during filming, England experienced a rare heat wave, the temperature nearing 100 degrees Fahrenheit, and the studio's A/C ended up failing. He and Landau were stuck working inside spacesuits with temps reaching 120 degrees on set.
Act four (beginning with Maya transforming into the Kreno animal) opens with a piece of music that originated at the start of the deleted scene on The Metamorph (1976) where Tony and Sandra discuss Professor Bergman's death.
After quitting the series early in Season Two, Zienia Merton had decided to return starting with Catacombs of the Moon (1976). Normally, Yasuko Nagazumi would no longer be needed with Merton's return, but since "Catacombs" was filmed at the same time as this episode, they needed Yasko here. "The AB Chrysalis" also featured Sarah Bullen as Kate, formerly one of the many nonspeaking Main Mission background characters seen throughout Season One.
Sarah Douglas ("B"), Harry Fielder (medic), and Pam Rose (Command Center Operative) all appeared in Superman (1978).
The lift lowering the Eagle into the planet's interior will be seen later as a Moonbase Alpha launch pad lift in two episodes, even though the Alpha lifts are supposed to be cross-shaped.