Hell's Retriever

The Hell's Retriever is a Wonder Weapon and tactical item introduced in Mob of the Dead. The Hell's Retriever can be obtained by feeding six zombies to all three of the heads of Cerberus.

When thrown, it can pierce through multiple Zombies at once eventually returning to the player. It can also be charged, which adds more damage and distance. This can be done by holding down the tactical button for a maximum of two pulses. If the player throws it towards a Power-Up, it will retrieve the powerup and bring it back to the player.

Players will never lose the Hell's Retriever unless they bleed out. Throwing it does not get rid of it, as it takes a while for it to return to the the player. Additionally, the player has to wait for the four-second cooldown before it can be thrown again. The Hell's Retriever has the ability to one shot zombies when double charged until round 20. It is also very effective when fighting Brutus in the early rounds.

The Hell's Retriever can be upgraded into the Hell's Redeemer. It appears to be an instant-kill until at least round 35. In addition, it can be charged 3 times rather than two. To obtain the Redeemer: In co-op Zombies mode, all four players are able to get the Redeemer, but they must complete the process individually.
 * 1) The player must have built the plane.
 * 2) Obtain the Hell's Retriever.
 * 3) Fly to the Golden Gate bridge.
 * 4) Finish an entire round with a minimum of 30 zombies using only the Hell's Retriever. If done correctly, the player will hear a noise which sounds like a breath.
 * 5) Use the electric chairs to return to the prison.
 * 6) Find the lava pit under the Hellhound spawn next to the starting room.
 * 7) Throw the Hell's Retriever into the lava pit. If done correctly, the Hell's Retriever will not be returned to the player.
 * 8) Go to the laundry room and enter Afterlife mode. Once in Afterlife mode, head to the room where the Hell's Retriever can be found. The Hell's Redeemer will be in its place.

There is a way to get the upgraded Hell's Retriever by shooting the it at the hole where you obtained it. You know if you done correctly is you don't get it back. Go into Afterlife and go to the hole. You will be able to pick the "Hell's Redeemer" in Afterlife. Return to your body and it will appear in you HUD.

Trivia

 * The Hell's Retriever can bring dropped power-ups back to the player who threw it.
 * It is effective in killing Brutus in the early rounds.
 * The Hell's Redeemer is the first upgradable tactical grenade/item to appear in Zombies.
 * The Hell's Retriever is changed from a fiery apperance to a electrical one when it is upgraded to the Hell's Redeemer.