Colhemos, the Salvage Titan

Shroud, Reach, Trample, Vigilance
As an additional cost to cast Colhemos, the Salvage Titan, exile 2 artifact creature cards from your graveyard. Colhemos gets +X/+X, where X is the total combined power of the exiled cards.
Colhemos's base power and toughness are each equal to the number of artifacts in your graveyard.
{4}: Put the bottom card of your library into your graveyard.