He links up with former Swansea team-mate Rory Pitman who made his debut for the Scorpions on Sunday after signing from the Ospreys.
A prop or hooker in rugby union, the Neath-born Davies makes a return to The Gnoll where his rugby career started.
Davies will be playing Rugby League for the first time in nearly ten years when he makes his Scorpions debut.
He has spent the last four seasons at Swansea after spells at Coventry and Llandovery rugby union clubs.
Davies is in training with the Scorpions and will hope to make his debut in their next game, which is against Barrow Raiders at The Gnoll in Neath on Sunday 6th May (kick-off 3pm).
“Alun comes in at a good time for us when we’re not performing at our best and we need someone to give us a lift,” said Scorpions coach Dave Clark. “Alun could be the person to help us do that.
“He’s a great signing for us. He’s played Rugby League before so his knowledge of the game is good. We’re working on his fitness and helping him adapt back to Rugby League and we’ll get him in the team as soon as we can.”