A significant contributor to the Pirates cause in his time at the Mennaye Field, the Lincoln born full back has continued his fine form and developed into a fully fledged Aviva Premiership operator, gaining plaudits with every performance.
Cook has scored four tries to date in a Gloucester shirt, and his unique kicking style has produced 50 points. But it's his dependency under the high ball, solid defence and exhilarating breaks on the counter attack that have caught the eye in Cook's time in Cherry and White.
Cook spoke of his delight to have signed a new deal at Kingsholm:
"I'm thrilled to have the chance to extend my stay at such a great club and continue my rugby development. I've played in some great games in my Gloucester career to date, and I want to be part of many more.
"My time at the club has been amazing so far, and the boys around me have helped me to develop my game and push myself to make the step up from Championship to Premiership and European rugby.
"The fans have also been outstanding. To have the chance to run out to that Kingsholm roar and experience that matchday atmosphere is brilliant for me, and something I can't wait to experience more of."
Gloucester's Director of Rugby Nigel Davies is also delighted to have another member of his team signed up for the future.
"Rob's been fabulous. He came up from the Pirates, playing in the Championship, and he's really taken to the Premiership.
"He's evolved his game, he's developed his conditioning and he brings that little bit of experience to what is, in essence, a very young backline. He manages and controls things from the back there.
"He makes very few errors, tends to put the team in the right places and takes pressure off the team at the right times as well."