Cheapest priced copy (Commander Legends: Battle for Baldur's Gate): $0.39 at Card Kingdom, near mint, their price list as of .
Iron Mastiff 
Artifact Creature — Dog · 4/4 · Uncommon · Commander Legends: Battle for Baldur's Gate · #317
Whenever this creature attacks, roll a d20 for each player being attacked and ignore all but the highest roll.
1—9 | This creature deals damage equal to its power to you.
10—19 | This creature deals damage equal to its power to defending player.
20 | This creature deals damage equal to its power to each opponent.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $0.39 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander Legends: Battle for Baldur's Gate | 317 | Uncommon | $0.39 | $0.49 |
One ruling from Wizards of the Coast
- 10 June 2022Once Iron Mastiff's triggered ability begins to resolve, no player may cast spells or activate abilities until it finishes resolving. Notably, this means that players may not take actions that would change Iron Mastiff's power after they know the result of the rolls but before players are dealt damage.