Cheapest priced copy (Aetherdrift): $0.49 at Card Kingdom, near mint, their price list as of .
Guardian Sunmare 
Creature — Horse Mount · 5/5 · Rare · Aetherdrift · #334
Ward {2}
Whenever this creature attacks while saddled, search your library for a nonland permanent card with mana value 3 or less, put it onto the battlefield, then shuffle.
Saddle 4
Legal inCommanderBrawlStandardPioneerModernLegacyVintage
Not legal inPauper
6 printings · $0.49 to $3.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Aetherdrift | 15 | Rare | $0.49 | $0.49 |
| Aetherdrift | 334 | Rare | $0.49 | $1.49 |
| Aetherdrift | 429 | Rare | — | $2.99 |
| Aetherdrift | 533 | Rare | — | $3.99 |
| Aetherdrift Promos | 15p | Rare | $0.49 | $1.99 |
| Aetherdrift Promos | 15s | Rare | — | $0.79 |
6 rulings from Wizards of the Coast
- 7 February 2025“Saddled” isn’t an ability that a creature has. It’s just something true about that creature. It won’t stop being saddled until the turn ends or it leaves the battlefield.
- 7 February 2025You may activate a permanent’s saddle ability even if that permanent is already saddled.
- 7 February 2025“Saddle N” means “Tap any number of other untapped creatures you control with total power N or greater: This permanent becomes saddled until end of turn. Activate only as a sorcery.”
- 7 February 2025If a permanent becomes a copy of a saddled Mount, the copy won’t be saddled.
- 7 February 2025Creatures with saddle can attack or block as normal even if they aren’t saddled.
- 7 February 2025An ability that triggers when a creature “attacks while saddled” will trigger only if that creature was saddled when it was declared as an attacker.