"Penguin is a Girl's Best Friend" finds Burgess Meredith back after an absence of only one week, paired not with The Joker but with Carolyn Jones as Marsha, Queen of Diamonds, the second and last three part storyline from the second season, designed to be edited into a feature film for the overseas market. Penguin is already at work on an armored car robbery when the Batmobile pulls up, the Caped Crusaders making quick work of his men, before Chief O'Hara arrives to put a damper on Batman's triumph. The Chief surprises Batman with the knowledge that the master of foul play has turned to filmmaking, as president of Penguin Pictures, intending to sue the city for Batman's blunder unless he signs a contract to star in the movie, set in the days of the Roman gladiators. This turn of events is enough for Marsha to sign on as investor and leading lady, still intending to snare Batman with lipstick dipped in love potion created by her Aunt Hilda (Estelle Winwood). The Gotham City Legion of Decency prevents the shooting of Marsha's naked milk bath, but not before one enterprising crewman peeks under his blindfold! Carolyn Jones was a better choice than Zsa Zsa Gabor, but continues to spout as many 'darlings' as the much married diamond expert. The climactic cliffhanger takes place at a museum of antiquities, the Dynamic Duo set to be catapulted across town to certain death, as Penguin rejoices: "I'm sure you'll make a big splash at the other end of your journey!"