Larry Hagman's last role was as Nelson, a Costco employee serving up samples to customers, on the CBS prank show "I Get That a Lot," which aired Wednesday night.
The appearance was shot just weeks beforeof complications from cancer in November at age 81.
Hagman was among several celebrities who took on everyday jobs and tried to convince the public that they're not famous. He was offering chocolate chip cookies with barbecue sauce to shoppers, many of whom recognized him, although one woman kept saying Hagman was taller.
Hagman continued to deny he was famous, adding, "I wouldn't be doing this job" or "he (Hagman) is a much older guy."
Hagman was in the middle of filming a new season of the revived show "Dallas" when he died and will be seen as J.R. Ewing later this year when the season airs.
Others who took part in the CBS show were Olympian and "Keeping Up With the Kardashians" star Bruce Jenner, actress Jane Seymour, race car driver Jeff Gordon, "The Amazing Race" host Phil Keoghan and comedian Cheech Marin.