Cheapest priced copy (Magic Origins): $0.35 at Card Kingdom, near mint, their price list as of .
Wild Instincts 
Sorcery · Common · Magic Origins · #206
Target creature you control gets +2/+2 until end of turn. It fights target creature an opponent controls. (Each deals damage equal to its power to the other.)
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Magic Origins | 206 | Common | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 22 June 2015You must target both a creature you control and a creature an opponent controls to cast Wild Instincts.
- 22 June 2015If the creature an opponent controls is an illegal target as Wild Instincts tries to resolve, but the creature you control is still a legal target, the creature you control will get +2/+2, but the creatures won’t fight. Neither creature will deal or be dealt damage during the resolution of Wild Instincts.