Whenever Novablast Wurm attacks, destroy all other creatures.
3/1/2010 Novablast Wurm’s ability triggers and resolves during the declare attackers step, before blockers can be declared.
3/1/2010 Novablast Wurm’s ability destroys all players’ creatures (except Novablast Wurm), including yours.
3/1/2010 If two Novablast Wurms attack, they’ll destroy each other. This happens before they can deal combat damage.