Bog Hoodlums [Lorwyn]

Bog Hoodlums can't block.
When Bog Hoodlums enters the battlefield, clash with an opponent. If you win, put a +1/+1 counter on Bog Hoodlums. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)