Deathtouch
Whenever a creature you control with deathtouch attacks, each opponent loses 1 life and you gain 1 life.
Whenever a creature you control with deathtouch deals damage to a planeswalker, destroy that planeswalker.
Hooded Blightfang's triggered abilities trigger when it attacks and when it deals damage to a planeswalker, as long as it still has deathtouch.
In a Two-Headed Giant game, Hooded Blightfang's middle ability causes the opposing team to lose 2 life and you to gain 1 life.