Cheapest priced copy (Commander 2015): $0.49 at Card Kingdom, near mint, their price list as of .
Awaken the Sky Tyrant 
Enchantment · Rare · Commander 2015 · #24
When a source an opponent controls deals damage to you, sacrifice this enchantment. If you do, create a 5/5 red Dragon creature token with flying.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander 2015 | 24 | Rare | $0.49 | — |
2 rulings from Wizards of the Coast
- 4 November 2015Awaken the Sky Tyrant will trigger once for each source an opponent controls that deals damage to you, but you can sacrifice it only once.
- 4 November 2015If Awaken the Sky Tyrant isn’t on the battlefield as its ability resolves, you can’t sacrifice it. You won’t get the Dragon in that case.