Cheapest priced copy (The List): $0.35 at Card Kingdom, near mint, their price list as of .
Sun-Crowned Hunters 
Creature — Dinosaur · 5/4 · Common · Ixalan · #164
Enrage — Whenever this creature is dealt damage, it deals 3 damage to target opponent or planeswalker.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
2 printings · $0.35 to $0.79 at Card Kingdom
3 rulings from Wizards of the Coast
- 29 September 2017If your life total is brought to 0 or less at the same time that Sun-Crowned Hunters is dealt damage, you lose the game before its enrage ability resolves.
- 19 January 2018If multiple sources deal damage to a creature with an enrage ability at the same time, most likely because multiple creatures blocked that creature, the enrage ability triggers only once.
- 19 January 2018If lethal damage is dealt to a creature with an enrage ability, that ability triggers. The creature with that enrage ability leaves the battlefield before that ability resolves, so it won’t be affected by the resolving ability.