Peacock, 20, holds a British passport and won’t count on the club’s overseas quota, and follows back Kayle Connor to the club from Down Under.
He said: “Signing with the Scorpions for 2013 and moving to Wales leaves me with mixed emotions. Both nervous and extremely excited. It’s a great opportunity for me and I’m really looking forward to the challenge of a new and different competition. I can’t wait to get over to meet the boys and kick the season off.”
Peacock came through the youth ranks at Cronulla, and played alongside Welsh international Tyson Frizell for the Sharks’ Under 20s side last season.
Scorpions’ coach Dave Clark said: “We’re delighted that Haydn has agreed to join the Scorpions for 2013. He is a versatile player who can turn out in a number of positions and is certain to strengthen the side as we aim for a strong season.”
This signing takes the number of Scorpions’ foreign imports for 2013 to four with Peacock joining former Brisbane Broncos Academy player Connor, Tongan international James Tutuila and the already established Ben Gilbert at The Gnoll.