Cheapest priced copy (Game Night: Free-for-All): $0.49 at Card Kingdom, near mint, their price list as of .
Ancient Hellkite 
Creature — Dragon · 6/6 · Rare · Magic 2011 · #122
Flying
{R}: This creature deals 1 damage to target creature defending player controls. Activate only if this creature is attacking.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
3 printings · $0.49 to $0.59 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Game Night: Free-for-All | 68 | Rare | $0.49 | — |
| Magic 2011 | 122 | Rare | $0.49 | $0.49 |
| Magic 2011 Promos | 122★ | Rare | — | $0.59 |
One ruling from Wizards of the Coast
- 15 August 2010After Ancient Hellkite is declared as an attacker, or is put onto the battlefield attacking, its second ability may be activated. Unless Ancient Hellkite leaves combat, it continues to be attacking (so its ability may still be activated) through the end of combat step.