Nocturnal Feeder

• WWizards of the Coast2020-06-23
  Official Ruling
  In a Two-Headed Giant game, Nocturnal Feeder’s ability causes the opposing team to lose 4 life and you to gain 2 life.
• WWizards of the Coast2020-06-23
  Official Ruling
  If your life total is brought to 0 or less at the same time that Nocturnal Feeder is dealt lethal damage, you lose the game before its ability goes on the stack.

Rulings via Scryfall