Cheapest priced copy (Magic 2015): $0.59 at Card Kingdom, near mint, their price list as of .
Siege Dragon 
Creature — Dragon · 5/5 · Rare · Magic 2015 · #162
Flying
When this creature enters, destroy all Walls your opponents control.
Whenever this creature attacks, if defending player controls no Walls, it deals 2 damage to each creature without flying that player controls.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.49 to $0.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Magic 2015 | 162 | Rare | $0.59 | $0.49 |
| Magic 2015 Promos | 162 | Rare | — | $0.79 |