The 28-year-old represented Cardiff Blues in 2010, and has also played club rugby union for Pontypridd and Cross Keys.
Despite starting the 2015/16 union season with WRU Championship side Pontypool, he has now swtiched full-time to rugby league.
“I’ve always loved watching rugby league and he idea of playing has always appealed to me too, but I’ve never quite had the chance to play it with rugby union contract commitments,” said Baller.
“But having suffered a shoulder injury and with it being end of the regular season, I contacted Paul Emanuelli to see if I could come along to get some fitness work done with the potential of getting a few games, which I did with the Cougars.
“I played some rugby league training games when I was in college a few years back and up until last year I hadn’t really played any, but managed to get three games in with Valley Cougars which was a great experience.
“Pre-season training is just about to start and I want to work hard on learning the game in more depth and under Phil Carleton I think I’ll be able to do that.
“On a personal note, I just want to compete for a place in the squad week in week out. With having less Rugby League experience than most of the guys there I’m going to have to work that bit extra to make this happen.
“Once I’m there it’s about improving my game all the time to stay in the match day squad. As a team, I know our target is to finish as high as possible in the league.”
Scorpions’ coach Phil Carleton is delighted to have the goal-kicking winger on board for 2016.
“I’m really pleased to have got Kris on board,” he said.
“He has a great skill set and is a natural rugby player. True, the majority of his rugby has been played in the other code but having watched him play a few games of league, I know he’s got a lot of potential.
“It’s up to him now to get his head down and show everyone what he can do.”