User blog comment:PvZ/Survival Endless Setup/@comment-3392003-20110131160929/@comment-50.103.15.109-20120816144709

They are, only if you have 6 of them. When a arrow comes down, I either have a ice shroom ready to freeze them or I put down a ice shroom and wake it up. That way, you can give them a good amount of damage while the are freezed.