Cheapest priced copy (The List): $3.99 at Card Kingdom, near mint, their price list as of .
Sleeper Agent 
Creature — Phyrexian Minion · 3/3 · Rare · The List · #10E-178
When this creature enters, target opponent gains control of it.
At the beginning of your upkeep, this creature deals 2 damage to you.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
3 printings · $3.99 to $22.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Tenth Edition | 178 | Rare | $4.49 | $22.99 |
| The List | 10E-178 | Rare | $3.99 | — |
| Urza's Saga | 159 | Rare | $5.49 | — |
One ruling from Wizards of the Coast
- 4 October 2004This card is a bit weird. When it enters under your control, you give control of it to an opponent. After that it damages them each turn because the "you" on the card means its controller.