RSA regular Adrian Manning had put a lot of time, effort and expense into building the display, even importing the latex mask from the US.
Mr Lynch said: "Whoever it is, you're pinching off the RSA. These are people who fought for you, you miserable bastards."
He also urged anyone who had information on Freddy's whereabouts to call Kerikeri police on (09) 407 9211.
Mr Manning landed the biggest snapper of the contest (12.77kg), helping the RSA to their second Big Balls win in a row, with a top 10 average weight of about 6.6kg compared with Homestead's 5.2kg. This year, 53 people took part.
If Freddy cannot be found, he is likely to be replaced by Darth Vader next year.