Not legal in Standard, Pauper, Alchemy, Standard Brawl, Pauper Commander, Premodern, Pre-EDH, Old School
Notes & Rules Information
If 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.
(2018-01-19)
If 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.