Legend tells us of a man, a hero in a tortured land, where Señoritas lived in fear. Their lonely nights in deep despair, he was EL BURRO! (Hee-Haw, Hee-Haw). Across the fields, across the plains. He ran so fast he dodged the rain. He was El Burro! He hurried in to save the day, gun in hand, and thrice they say. He was strong like a Mule, he was stubborn like a Mule, he even kicked like a Mule, El Burro! (El Burro!). A man not equal, so they say. But some and more, it's just the way! He was El Burro! He was EL BURRO! EL BURRO! (Hee-Haw, Hee-Haw).
— Mule Kick's Jingle
ARRIIIBAA!!! QUE PASA!!! When you're 'round Louisiana, now into Texarkana. Lord you want more firepower, MULE KICK! (Hee-Haw, Hee-Haw). Come and get your hands on more guns, that's what I'm home did, I guarantee, take more if you dare. HOW 'BOUT 3 GUNS, MON CHER?! MULE KICK! (Hee-Haw, Hee-Haw, Hee-Haw).
Mule Kick is a Perk-a-Cola that is featured in the game mode Zombies and Cyborg Rising. It was introduced in the Call of Duty: Black Ops Zombies map Moon. It allows the player to hold three weapons at once. It costs 4000 points to purchase, making it tied with Widow's Wine for the most expensive Perk-a-Cola. When purchased, the player will not see any effect except for the symbol appearing on their HUD. When the player goes to buy their next weapon, the prompt will still state that taking it will replace the currently selected weapon, but in reality it will take its place in the third slot. The color of this perk is dark green (although the color of the drink is dark red) and the icon is three pistols, one behind the other from bottom to top.
If a player is downed whilst this perk is in effect, or if a Space Monkey succeeds in removing it in Ascension, the player will lose the perk, and by extension, the third weapon slot.
In the update that occurred on September 27, 2011, Mule Kick is now available on all maps in Call of Duty: Black Ops for PlayStation 3 and Xbox 360. It came to PC along with Patch 1.15 on October 11. However, the player must be connected to PlayStation Network, Steam or Xbox LIVE for Mule Kick to appear on other maps than Moon.
The Mule Kick machine has a large, bizarre shape with a red, white, and green paint job. The machine is on a white pedestal. On the front of the machine are red painted dots and ammo belts can be seen, and a sombrero, moustache and two crossed ammo belts can be seen on the red dispenser with the words "Uno mas!!" at the bottom of it. On the left of that are 6 empty bottle compartments aligned vertically. At the top is a quote that says "Mule Kick" and a small price that quotes "10¢" on the right of it. Above that is a circular sign with the Mule Kick icon on it.