Andrew McCullough will be St George Illawarra's long-term replacement for Cameron McInnes after he signed a three-year deal with the NRL club.
Brisbane confirmed on Monday they had released the veteran hooker, paving the way for him to join his former coach Anthony Griffin at the Dragons.
The deal is a significant gamble on McCullough's longevity, given he will be playing well beyond his 33rd birthday and into a 16th season.
It also reunites him with fellow former Broncos players Ben Hunt and Corey Norman, with the trio all playing together in Brisbane's spine under Griffin.
"It's no secret that we have been interested in Andrew McCullough for a while now and we're pleased to see him finally sign with the Dragons," Dragons head of football Ben Harran said.
"Signing a player of Andrew's calibre will no doubt inject plenty of experience into our team and wider squad.
"While his style of play will complement the development of the exciting young talent we have here at the Dragons."
The move marks the end of an on-again, off-again relationship between McCullough and Brisbane after 260 NRL games at the club.
He began the season there last year, but moved to Newcastle after the COVID-19 lockdown.
He eventually succumbed to a serious hamstring injury, and returned to the Broncos over the off-season before his latest departure.
"He probably doesn't get a lot of credit for the things he does behind the scenes," senior Bronco Pat Carrigan said.
"I can't hold anything against Mac. I'm super excited for his future at the Dragons."