Cheapest priced copy (Magic Origins): $0.35 at Card Kingdom, near mint, their price list as of .
Ringwarden Owl 
Creature — Bird · 3/3 · Common · The List · #ORI-68
Flying (This creature can't be blocked except by creatures with flying or reach.)
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Magic Origins | 68 | Common | $0.35 | $0.49 |
| The List | ORI-68 | Common | $0.35 | — |
3 rulings from Wizards of the Coast
- 22 June 2015Any spell you cast that doesn’t have the type creature will cause prowess to trigger. If a spell has multiple types, and one of those types is creature (such as an artifact creature), casting it won’t cause prowess to trigger. Playing a land also won’t cause prowess to trigger.
- 22 June 2015Prowess goes on the stack on top of the spell that caused it to trigger. It will resolve before that spell.
- 22 June 2015Once it triggers, prowess isn’t connected to the spell that caused it to trigger. If that spell is countered, prowess will still resolve.