Cheapest priced copy (Commander Legends): $0.49 at Card Kingdom, near mint, their price list as of .
Bladegriff Prototype 
Artifact Creature — Griffin · 3/2 · Rare · Commander Legends · #300
Flying
Whenever this creature deals combat damage to a player, destroy target nonland permanent of that player's choice that one of your opponents controls.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
3 printings · $0.49 to $0.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander Legends | 300 | Rare | $0.49 | $0.49 |
| Commander Legends | 690 | Rare | $0.79 | $0.99 |
| Outlaws of Thunder Junction Commander | 253 | Rare | $0.49 | — |
2 rulings from Wizards of the Coast
- 10 November 2020Even though the player who was dealt damage chooses the target for Bladegriff Prototype's ability, you are the controller of the ability.
- 10 November 2020If an opponent dealt damage by Bladegriff Prototype leaves the game before the triggered ability goes on the stack (most likely because that player's life total was reduced to 0 or less in combat), you choose another opponent to choose the target permanent.