I think his name was Garrick Morgan?
Apparently some big-time union player (played regularly for Australia I think ... I was only 14 at the time and showed as much interest in that game as I do now ... zilch) who came across to League to play for the new South Queensland Crushers in 1995 or 1996.
Barely lasted a season in the top grade in a team that finished at the arse-end of the table. Went back to union the following year, never to be heard of again.
Alternatively, there was another code-crosser in 1999 that lasted something like 2 games. Maybe 3.
The long-time joke in Newcastle-town. Greg bloody Smith.
NFL player (supposedly). Trialled, somehow got into a First-Grade side of the Knights who were filled with premiership players, test and Origin reps, ect. A real masterstroke by then-coach Warren Ryan. Had a terrible game against Canterbury and was subsequently dropped. Again, never to be heard of since. Last I heard, shortly later, he was cut as he'd lied about his past sporting career, and got deported for visa issues.