Cheapest priced copy (Jumpstart 2022): $0.35 at Card Kingdom, near mint, their price list as of .
Ornery Dilophosaur 
Creature — Dinosaur · 2/2 · Common · Jumpstart 2022 · #700
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever this creature attacks, if you control a creature with power 4 or greater, this creature gets +2/+2 until end of turn.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Jumpstart 2022 | 700 | Common | $0.35 | — |
| Core Set 2021 | 194 | Common | $0.35 | $0.49 |
4 rulings from Wizards of the Coast
- 23 June 2020Ornery Dilophosaur gets just +2/+2, no matter how many creatures you control with power 4 or greater.
- 23 June 2020If Ornery Dilophosaur's power is raised to 4 or greater, its ability triggers when it attacks.
- 23 June 2020Once Ornery Dilophosaur's ability has resolved, it keeps +2/+2 for the rest of the turn even if you no longer control a creature with power 4 or greater.
- 23 June 2020If you don't control a creature with power 4 or greater immediately after Ornery Dilophosaur attacks, its ability doesn't trigger. If you don't control one as the ability resolves, it has no effect. It doesn't have to be the same creature at both times, however.