The veteran actor, best known for his portrayal of scheming oil baron J.R. Ewing in the original version of the soap opera, which ran from 1978 to 1991, passed away at a hospital in Texas on Friday (23Nov12) after suffering complications from his battle with cancer.
His Dallas co-stars old and new - including Linda Gray, Patrick Duffy, Brenda Strong and Jesse Metcalfe - paid tribute to the star after news of his death emerged, and now Henderson, who plays John Ross Ewing Iii in the drama, has spoken out to remember Hagman.
Posting a picture of the pair joking around on set to his Twitter.com page, Henderson hails Hagman as a "mentor and a friend" and insists he will always be grateful for the time they spent working together.
He writes, "Wow. What an incredible last 2 years I've had with this man. Not only an icon and a legend, but also a mentor and a friend.
"Larry you changed my life and I am forever grateful for the gift that was getting to work with you. I'll always be ur (your) son 'from tip to tail' Rest in peace my friend."
Hagman was partway through filming the second series of the Dallas revamp when he died, and the show's writing team is set to alter the planned storyline in the aftermath of the tragedy.