Blood Tap

Blood Tap  is a basic  Death Knight  spell card.

 How to Get
Blood Tap x 2 are automatically included in all players' collections.

Golden Blood Tap is a reward for raising a Death Knight to a high level.

Blood Tap is soulbound and cannot be crafted or disenchanted.

Strategy
Blood Tap functions in a similar way to Death Pact, destroying a friendly minion to support the Death Knight. However, that's where the similarity stops. Blood Tap can be cast on any minion, large or small, with the same effect - summoned minions like Boom Bot or Whelp are ideal targets, as they are almost useless (and casting Blood Tap on Boom Bot will trigger its deathrattle).

Lore
Blood Tap, in World of Warcraft, is a Death Knight talent that causes Runic Power use to generate Blood Charges, which can be expended to recharge depleted runes.