Spire Serpent | Magic: The Gathering
Formats Spire Serpent is Legal in
Official Oracle Text for Spire Serpent
Metalcraft — As long as you control three or more artifacts, Spire Serpent gets +2/+2 and can attack as though it didn't have defender.
Official Rulings for Spire Serpent
6/1/2011 : If Spire Serpent has been declared as an attacker, and you stop controlling three or more artifacts later in combat, Spire Serpent continues being an attacking creature until combat ends.