A good card for this strategy would be a cEDH staple called Underworld Breach, which makes each nonland card in the user's graveyard have escape, with the escape cost being equal to that card's mana cost plus exiling three cards from the user's graveyard
You could put it in a fat pack box, tape that up with another packing slip or copy of the shipping label attached, then put that inside a small reused amazon/ebay box with some reused packing material (you probably have some lying around)
Minsc and Boo are seen riding upon a fierce mighty dragon in this beautiful reprint of the Timeless Heroes card, showing them in the midst of their usual hero business
As your creatures deal combat damage to your foes, you draw cards, nice card flow, and synergy with the mass trample giving Brawn or Filth with Urborg or against folks with Swamps naturally
There are, of course, weaknesses to a mill strategy some players include cards that prevent themselves from losing to an empty library, like Ulamog, the Infinite Gyre