Cheapest priced copy (Fifth Edition): $0.79 at Card Kingdom, near mint, their price list as of .
Xenic Poltergeist 
Creature — Spirit · 1/1 · Uncommon · Antiquities · #20
{T}: Until your next upkeep, target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
6 printings · $0.79 to $3.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Fourth Edition Foreign Black Border | 173 | Rare | — | — |
| Fourth Edition | 173 | Rare | $1.29 | — |
| Fifth Edition | 206 | Rare | $0.79 | — |
| Antiquities | 20 | Uncommon | $3.49 | — |
| Renaissance | 69 | Uncommon | — | — |
| Rinascimento | 60 | Uncommon | — | — |
2 rulings from Wizards of the Coast
- 4 October 2004Wears off at the beginning of the upkeep, not during upkeep.
- 1 August 2008A noncreature permanent that turns into a creature can attack, and its {T} abilities can be activated, only if its controller has continuously controlled that permanent since the beginning of their most recent turn. It doesn't matter how long the permanent has been a creature.