Muldoon had a short stage career in a New Zealand production of The Rocky Horror Show, held at Auckland's His Majesty's Theatre (demolished soon after the production ended), starring as the narrator. He also had minor television appearances on commercials for Panasonic (when it changed its brand name in New Zealand from "National") and in the television series Terry and the Gunrunners (as Arnos Grove) and in The Friday Frights (as the vampiric host 'Count Robula'); he also hosted a talkback radio show entitled Lilies and Other Things, referencing his favourite flower on Radio Pacific.
