Struggle for Survival

Struggle for Survival enters the battlefield with X struggle counters on it.
Whenever a creature you control is blocked, it gets +X/+X until end of turn, where X is the number of struggle counters on Struggle for Survival. Then, remove a struggle counter from Struggle for Survival.
"When your life is on the line, you will do anything to survive." ~Aroi of the Thunder Spear