V'ger

Flying, Trample
V'ger costs {1} less to play for each nonartifact creature in play.
V'ger's power and toughness are each equal to the number of artifacts in play
At the beginning of each player's upkeep, that player sacrifices a nonland, nonartifact permanent. If they can't, they lose the game.
It knows only that it needs, Commander. But, like so many of us... it does not know what.
-Commander Spock