Carnage Kraken

Flash (You may cast this spell any time you could
cast an instant.)
{6}{u/b}{u/b}: Monstrosity 4. (If this creature isn't
monstrous, put four +1/+1 counters on it and it
becomes monstrous.)
When Carnage Kraken becomes monstrous,
choose one —
• Destroy target creature an opponent controls.
• All creatures able to block Carnage Kraken this
turn do so.