What is Deathrattle in Hearthstone?
Hearthstone has many card effects that are common enough that they get their own keyword - a word or two that immediately tells you how the card works. Let's take a look at the Deathrattle keyword.
Does something when it dies.
Deathrattle is one of the most common keywords in Hearthstone working as a thematical and mechanical counterpart to the ever-present Battlecry mechanic.
Keywords that Work Great with Deathrattle
An artificial Deathrattle (from a card such as Ancestral Spirit) can be added to a Charge/Rush minion to attack a minion, and then come back to life, which will allow it to attack again thanks to Charge/Rush.
Taunt is also good with Deathrattles. Your opponent will be forced to attack the Taunt minion until it dies, forcing them to trigger its Deathrattle.
Playing Against Deathrattle in Hearthstone
Acknowledging the time it's most advantageous for the enemy player for the Deathrattle to trigger is key. Deathrattles are also delayed for a turn, so use this to gain a leverage on playing against it If your opponent controls a minion with a strong Deathrattle, you can ignore it and focus on their other targets to avoid triggering the Deathrattle. Conversely, triggering a strong Deathrattle right away is sometimes better to get it "out of the way" right then and there. If a Deathrattle summons a minion, it's sometimes best to kill that minion, and then the summoned minion right away when it's possible so it can't make a favorable trade later.
Silence will also neutralize any Deathrattles on a minion (as well as any other effect and enchantment it might have).
Example Hearthstone Deathrattle Cards
Loot Hoarder is an extremely simple card that will likely be the very first Deathrattle minion you encounter in the entire game. He's aggressively statted and will draw you a card when it dies. Loot Hoarder sometimes sees meta play, and is often a great "filler" card for your deck if you're missing 1 or 2 cards in your deck and are not sure what to add to it.
Ancestral Spirit is a Shaman spell that gives a minion a Deathrattle that will resummon the minion with a fresh, clean slate. Ancestral Spirit rarely sees play, but can be quite strong when put on a large, Taunt minion.
Terrorscale Stalker allows you to take instant advantage of a Deathrattle effect. The minion will also keep its Deathrattle meaning that it will trigger again when it dies.
N'Zoth, the Corruptor is an extremely strong card that will often turn the tides of battle, allowing you to summon several strong Deathrattle minions. This not only allows strong Deathrattles to trigger again, but it will put a huge amount of presence on the board. If you're opponent can't deal with the huge board created, this will often simply win the game outright. N'Zoth is an extremely strong card recommended for and Wild deck that specializes in Deathrattles. Note that the distinction "Deathrattle minion" means that the minion needs to naturally have a Deathrattle for it to be resummoned. A non-Deathrattle minion given an artificial Deathrattle through a card effect will not be resurrected by N'Zoth.