Kazrek, Heir of Jekkad

Menace, Trample, Bloodthirst 3
Other creatures you cast gain Bloodthirst X, where X is the number of +1/+1 counters on Kazrek.
Whenever your opponent casts a spell targeting Kazrek, you may remove a +1/+1 counter from him, sacrifice a creature, and pay 3 life. If you do, counter that spell.