Cheapest priced copy (Rivals of Ixalan): $0.35 at Card Kingdom, near mint, their price list as of .
Squire's Devotion 
Enchantment — Aura · Common · Rivals of Ixalan · #25
Enchant creature
Enchanted creature gets +1/+1 and has lifelink.
When this Aura enters, create a 1/1 white Vampire creature token with lifelink.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
1 printing · $0.35 to $1.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Rivals of Ixalan | 25 | Common | $0.35 | $1.49 |
2 rulings from Wizards of the Coast
- 19 January 2018You need a creature for Squire's Devotion to target as you cast it. There's no way to have it enter the battlefield attached to the Vampire token it'll create.
- 19 January 2018If the creature this Aura would enchant is an illegal target by the time Squire's Devotion tries to resolve, the Aura spell doesn't resolve. It won't enter the battlefield, so its ability won't trigger.