Deal 1 damage to a minion. If that kills it, draw a card.
If your spells look like horrifying skulls, let's be honest, you should get to draw some cards.
 How to get
Mortal Coil x 2 are a reward for raising a warlock to level 4.
In addition to the obvious removal potential, it is important to note that this spell can be cast at your own minion in order to draw a card (particularly useful in decks that are designed to draw as many cards as possible). It can also be played as a last ditch effort to draw a card that could save you from losing (such as a taunt) when at low life.
Mortal Coil is a talented warlock spell from World of Warcraft. It causes the target to run in horror for 3 seconds, and restores a portion of the warlock's health. It is very useful as a form of crowd control, as well as a regular method of maintaining health levels.