Craig, along with Mark are my top 2 suspects.

Craig as the funny, fat friend is a good cover and we saw a couple contestants throw that out there earlier on in the season as well as acknowledging that he can hide behind his unathleticism and say that he is still trying while at the same time costing the team money.

He has done some shady things in the game and it's believable that he would deceive many of the woman and Bobby who may have not been paying attention to him as the Mole.