Specimen Tank

{t}: Add {u}
Specimen Tank enters the battlefield with four time counters on it.
The first time a player mills a card each turn
or at the beginning of your upkeep, Remove a
time counter from Specimen Tank.
If Specimen Tank has no time counters on it, destroy it and create a 0/2 crab creature token
with two +1/+1 counters on it.