Fernando Torres

It wasn't intended that the first three players on this list would be Spanish, but that's how it turned out.
Fernando Torres signed for Liverpool and quickly became a fan favourite, much as Mo Salah has since done. He scored consecutive hat-tricks on his way to 24 league goals (33 in all competitions), breaking Ruud Van Nistelrooy's record for the most goals by a foreign player in a debut season - a record since eclipsed by that man Mo.
He couldn't keep up the form into the 2008-09 season though, and only managed half as many goals in his sophomore year.
He suffered a few injuries the next season and didn't play as many games as a result, but still managed 18 in 22 in the league, and would of course go on to win the World Cup the year after.