As Six-y Beast enters the battlefield, you secretly put six or fewer +1/+1 counters on it, then an opponent guesses the number of counters. If that player guesses right, sacrifice Six-y Beast after it enters the battlefield.
Near Mint - £0.20
Lightly Played - £0.20
Moderately Played - £0.20
Heavily Played - £0.10
Damaged - £0.10
Near Mint Non English - £0.20
Lightly Played Non English - £0.20
Moderately Played Non English - £0.20
Heavily Played Non English - £0.10
Damaged Non English - £0.10