The Israel international has moved from Belgian outfit Standard Liege on a six-month loan and could yet secure a permanent switch.
He told Celtic's official website: "Celtic are a very big club and even when I was young I always knew about the club, so when I got the opportunity to come I didn't need to think twice about it.
"Everything excites me about joining Celtic. I know a lot about the history of the club and how big it is. And it's always exciting to come to a new place - the fact I have to change country, make new friends and meet new staff.
"I know this is one of the biggest clubs in the world, they have won a lot of championships in Scotland and are the biggest club in Scotland. They also have a lot of history in European competition.
"I have heard the Celtic supporters are incredible and that there is a fantastic atmosphere in the stadium, and I'm looking forward to experiencing that."
Celtic look set to land a second consecutive Clydesdale Bank Premier League title after building up a nine-point advantage on home soil. But with a blockbuster tie against Juventus to come in the Champions League next month, Gershon admitted the lure of top-class European action was a major attraction.
"I am very happy and excited at this opportunity and I'm ready to start," he added.
"It means we have a lot of games to play but I have been in the same situation at Standard last year with the Europa League and cups as well. I know there are a lot of big games to play and this is good.
"I saw the game against Barcelona and it was a really good game. I've played in the Champions League before with Standard but not after the group stages, so this will be a good adventure. All my thoughts now are working and succeeding with Celtic - this is my goal."