The new deal will tie the 21-year old to the club until at least the end of the 2022 season.
Cowboys Director of Football Peter Parr was thrilled to see the homegrown talent put pen to paper.
“Reuben has been a part of our club for a long time, coming through our academies and development pathways system and unfortunately he had a lot of bad luck with injury, but through hard work and determination, he’s been able to overcome that and become a quality NRL player,” Parr told cowboys.com.au.
“We’re delighted he’s accepted a new two-year deal to stay with our club because there is no doubt he has a long-term future in the NRL.
“We believe we now have two of the best young hookers in the NRL in Reuben and Reece Robson.”
Coming through the Cowboys Junior Pathways Programs, ACL injuries cruelled three consecutive seasons for Cotter from 2016 to 2018.
He made his NRL debut in 2019 and has now played 15 first-grade games.
The Sarina Crocodiles junior is staying in NQ!#ridemcowboys
— NQ Cowboys (@nthqldcowboys) September 30, 2020