Cheapest priced copy (Odyssey): $0.35 at Card Kingdom, near mint, their price list as of .
Still Life 
Enchantment · Uncommon · Odyssey · #275
{G}{G}: This enchantment becomes a 4/3 Centaur creature in addition to its other types until end of turn.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Odyssey | 275 | Uncommon | $0.35 | $0.49 |
One ruling from Wizards of the Coast
- 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.