And Dragons captain Willis insists his new-look side will benefit from the 94-cap star's help ahead of their Magners League opener with Ulster at Rodney Parade next Friday.
Willis said: "Colin has great experience, a hard-nosed attitude but also a calming influence on the side.
"He has great knowledge, based around all his years in the game and you don't play just under 100 Tests for your country if you're not capable.
"He can help us prepare for games by sharing his experiences on what is to come.
"When Colin played for us, he was fantastic both on and off the field last season and as a captain, he was great too because he was a great second voice in supporting me. "It will be fantastic to use him as a resource this season for the players and the whole club."
Charvis had a colourful and controversial career during his 14 years in the top flight that included the 2001 British Lions tour and leading Wales to the 2003 World Cup and still holds the world record for the number of Test tries - 22 - for a forward.