No, no - I saw that. That's on his right hand. I mean a huge tattoo shaped like a paramecium on the INSIDE of his left forearm, which Kiefer has had since the very beginning of the series, waaaay back in season one.
By the way... the scars on Jack's back are awe-inspiring, but... I just wonder if the make-up people are gonna be able to get them all in exactly the right places whenever Kifer has to take off his shirt as the next few seasons progress. Watching closely, those scars may migrate around a bit.
Anyway, this is a REAL and very LARGE tattoo on the inside of Kiefer's left forearm. (Or maybe right...?)