Hammer Jammer [Unstable]

As Hammer Jammer enters the battlefield, roll a six-sided die. Hammer Jammer enters the battlefield with a number of +1/+1 counters on it equal to the result.
Whenever you roll a die, remove all +1/+1 counters from Hammer Jammer, then put a number of +1/+1 counters on it equal to the result.