Centre/winger Josh Simm will join Tigers in pre-season after spending 2023 with Wynnum Manly Seagulls, where he scored seven tries in 17 appearances.
The St Helens-born 22-year-old previously touched down nine times in 24 Betfred Super League games with his hometown club and on loan at Hull FC and Leigh.
“I’m absolutely buzzing, I really can’t wait,” said Simm, who has signed a two-year contract. “I left Saints last year and I wanted something new to challenge myself.
“I went over to Australia and really thrived over there so I’m excited to show people what I can do. I’ve got a lot of people to prove wrong and the full-time environment is going to help. I’ve had a good time in Australia and I’m excited to show people what I can do.”
Simm pledged to bring “full commitment and 100 per cent effort in every game”. He added: “I pride myself in being able to score from anywhere in attack.
“My defence has come on leaps and bounds over in Australia and I really want to prove to people what I can do.
“I left Saints under a bit of a cloud that I didn’t want in the Challenge Cup semi-final two years ago [a defeat to Wigan Warriors], but I’m a whole different player now - a whole year wiser, but I’ve loved it.”