SCP 169

Defender
Trample
SCP 169 enters the battlefield with 10 sleep counters on it. SCP 169 can't block if it has 5 or more sleep counters on it. At the beginning of your upkeep, remove a sleep counter from SCP 169. Whenever you remove a sleep counter from SCP 169, put 5 +1/+1 counters on it. Then, if there are no sleep counters on SCP 169, it can attack as though it didn't have defender, and can block an additional creature each combat.