Cheapest priced copy (Double Masters): $0.35 at Card Kingdom, near mint, their price list as of .
Clone Shell 
Artifact Creature — Shapeshifter · 2/2 · Uncommon · Scars of Mirrodin · #143
Imprint — When this creature enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom of your library in any order.
When this creature dies, turn the exiled card face up. If it's a creature card, put it onto the battlefield under your control.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Double Masters | 241 | Uncommon | $0.35 | $0.49 |
| Scars of Mirrodin | 143 | Uncommon | $0.35 | $0.49 |
3 rulings from Wizards of the Coast
- 7 August 2020As Clone Shell's first ability resolves, you must exile one of the cards you look at, even if none of them is a creature card.
- 7 August 2020If you gain control of another player's Clone Shell, you can't look at the face-down exiled card. However, if Clone Shell dies, you turn that card face up and, if it's a creature card, you put it onto the battlefield under your control.
- 7 August 2020As Clone Shell's second ability resolves, if the exiled card is not a creature card, it simply remains in exile face up.