Karn, Silver Golem USG/298

Set: Urza's Saga
Collector Code: USG/298
Name: Karn, Silver Golem
Type: Legendary Artifact Creature — Golem
Oracle text: Whenever Karn blocks or becomes blocked, it gets -4/+4 until end of turn. {1}: Target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value until end of turn.
Rarity: Rare