Ravenous Daggertooth — ruling 1

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.

Ravenous Daggertooth — ruling 2

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.

Ravenous Daggertooth — ruling 3

If your life total is brought to 0 or less at the same time that Ravenous Daggertooth is dealt damage, you lose the game before its enrage ability resolves.

Ravenous Daggertooth : règles, fonctionnement et interactions (MTG)

Ravenous Daggertooth is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Enrage — Whenever this creature is dealt damage, you gain 2 life.

How it works : Ravenous Daggertooth

Original English text — Wizards of the Coast / Scryfall

#1January 19, 2018· Wizards of the Coast
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.
No other card is named in this ruling.
#2January 19, 2018· Wizards of the Coast
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.
No other card is named in this ruling.
#3September 29, 2017· Wizards of the Coast
If your life total is brought to 0 or less at the same time that Ravenous Daggertooth is dealt damage, you lose the game before its enrage ability resolves.
No other card is named in this ruling.