This is the sea snake that attacks Dustin Hoffman in the scene where he is blind underwater being guided by Samuel L Jackson. As Sharon Stone was supposed to watching out for Dustin Hoffman's character but mysteriously disappears leaving Samuel to save the day! I found some things online about it:
according to this: http://connection.ebscohost.com/c/articles/25689318/sphere-creature-makeup-fx
It was done by Steve Johnson, Hiroshi Yada, Joe Colwell, Mark Killingsworth, Chris Nelson, and Todd Minobe.
Though the only person that has sphere listed in his credits on imdb is Joe Colwell
But IMDB shows this in the Trivia:
Joseph Hahn, the DJ in rock band Linkin Park, designed the sea snake through concept art.