Cheapest priced copy (Masters 25): $0.35 at Card Kingdom, near mint, their price list as of .
Griffin Protector 
Creature — Griffin · 2/3 · Common · Dominaria United · #18
Flying
Whenever another creature you control enters, this creature gets +1/+1 until end of turn.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
4 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Masters 25 | 17 | Common | $0.35 | $0.49 |
| Dominaria United | 18 | Common | $0.35 | $0.49 |
| Magic 2013 | 16 | Common | $0.35 | $0.49 |
| Core Set 2020 | 20 | Common | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 1 July 2012If Griffin Protector enters under your control at the same time as other creatures, its ability will trigger once for each of those creatures.
- 9 September 2022If more than one creature enters the battlefield at the same time, or if one or more other creatures enter the battlefield at the same time that Griffin Protector enters the battlefield, Griffin Protector's triggered ability triggers for each of them.