- "Ah, the power of a third arm. I know it well!"
- — Edward Richtofen
- "In what ways does this drink make me mule-like? Oh, it lets me carry more weapons. I was WAY off!"
- — Samuel J. Stuhlinger
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 carry 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.
Starting from the September 27, 2011 patch, 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 11th, 2011. However, the player must be connected to PlayStation Network, Steam or Xbox LIVE for Mule Kick to appear on other maps than Moon.
Within Call of Duty: Black Ops Cold War, the base ability of the perk allows the player to carry a 3rd weapon, with the Tier 1 upgrade granting the player an additional piece of equipment if able after crafting a piece of equipment. Tier 2 gives all enemies killed by the player a small chance of dropping ammo, with Tier 3 slowly refilling the ammo of stowed weapons from their stock. At Tier 4 the player is given a 25% chance of keeping non-retrievable equipment when used, and at Tier 5 the player's 3rd weapon is recovered upon repurchasing the perk if the player went down and lost Mule Kick as a result.
Uniquely as well in Call of Duty: Black Ops Cold War, the Perk Machine itself functions as a trap upon purchase of a can with each of the weaponry on the sides of the machine firing wildly.
- Nacht der Untoten - In the starting room, to the left of the M1 Carbine.
- Verrückt - In the corner of the first cell blocks, next to the stairs.
- Shi No Numa - In the starting room, to the left of the Gewehr 43.
- Der Riese - Below the path leading towards the teleporter in the automobile garage, next to the box location.
- Kino der Toten - In the portrait room, next to the door to the foyer.
- "Five" - In the war room, across the Mystery Box location.
- Ascension - Underneath the Speed Cola room, next to a barrier.
- Call of the Dead - At the back of the ship, right across the Mystery Box location.
- Shangri-La - In the waterfall area near the box location.
- Moon - Outside, near the teleporter to Area 51, and where the AK-74u can be purchased.
- Die Rise - Randomly spawns in one of the four elevator shafts in the building with the power switch. It trades these positions between games with Juggernog, Double Tap Root Beer and the Pack-a-Punch Machine.
- Mob of the Dead - Found on a boat across from the docks along with PhD Flopper as an unobtainable Easter egg.
- Buried - Found on top of the Gunsmith shop, in front of a Mystery Box spawn.
- Borough - Same as Buried.
- Origins - Found inside the excavation site, across from the staffs. Also purchasable by using the Der Wunderfizz machine.
- Shadows of Evil - In the Broken-down subway, near Widow's Wine.
- The Giant - Spawned randomly at any of the Perk-a-Cola machine locations, aside from the hidden machine.
- Der Eisendrache - Found in the corridor next to the big open hole below the room where the fire arrow can be acquired.
- Zetsubou No Shima - In the room before the underwater tunnels where the plant part for the KT-4 and the wheel part for the Pack-a-Punch Machine can be found.
- Gorod Krovi - Near the entrance to the Operations Bunker coming from the Department Store.
- Revelations - Inside the cafeteria in Mob of the Dead, where Deadshot Daiquiri would be in Cell Block.
- Nacht der Untoten (remastered version) - In the starting room, to the left of the RK5. Can also be obtained from the Der Wunderfizz machine or the Perkaholic or On the House GobbleGum.
- Verrückt (remastered version) - In the corner of the first cell blocks, next to the stairs. Can also be obtained from the Perkaholic or On the House GobbleGum.
- Shi No Numa (remastered version) - Will spawn randomly in one of the four huts. Can also be obtained from the Der Wunderfizz machine or the Perkaholic or On the House GobbleGum.
- Kino der Toten (remastered version) - In the portrait room, next to the door to the foyer. Can also be obtained from the Der Wunderfizz machine or the Perkaholic or On the House GobbleGum.
- Ascension (remastered version) - Underneath the Speed Cola room, next to a barrier. Can also be obtained from Perkaholic or On the House GobbleGum.
- Shangri-La (remastered version) - In the waterfall area near the box location. Can also be obtained from the Perkaholic or On the House GobbleGum.
- Moon (remastered version) - Outside, near the teleporter to Area 51, and where the AK-74u can be purchased. Can also be obtained from the Perkaholic or On the House GobbleGum.
- Origins (remastered version) - Found inside the excavation site, across from the staffs. Can also be obtained from the Der Wunderfizz machine or the Perkaholic or On the House GobbleGum.
- Mauer der Toten - Placed on the platform of the "Ghost Station" location, next to the pathway to the "Switch Control Room".
- Forsaken - Inside the Video Store.
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.
In Black Ops Cold War, the machine retains a similar shape while being fairly unique in appearance. The largest difference from this machine and the original is the fact that there is an animal skull at the top of the machine, as well as the machine being adorned with various firearms (specifically, the LW3-Tundra, XM4, Hauer 77 and Magnum. Another major difference is the middle of the machine, which now has a saloon-style swinging door in the middle (as well as a star carved out in the door). The machine also now serves cans instead of bottles.
- Tier I - Crafted equipment grants an additional equipment if able.
- Tier II - All enemies have a small chance to drop ammo.
- Tier III - Stowed weapons slowly refill from stock.
- Tier IV - 25% chance to keep non-retrievable equipment when used.
- Tier V - 3rd primary weapon is recovered when repurchasing Mule Kick.
- Fully Armed and Operational (25 / Bronze Trophy ) - In Moon, acquire 3 Pack-a-Punched weapons at the same time.
Call of Duty Online
- It is tied with Widow's Wine for the most expensive Perk-A-Cola, at 4000 points.
- According to Dempsey, Mule Kick tastes like beer, but Takeo states that it tastes like regular cola, making it a different taste for all the characters. In Origins, it tastes like soda pop to Dempsey.
- The perk's name is taken from the alcoholic mixer Mule Kick.
- There is a picture at the front of the machine that shows a sombrero, a mustache and a bandolier as if to take shape of a human form.
- On the machine, the machine has the two words "Uno Mas!" This means "One More!" in Spanish, referencing to how the drink gives the player "one more" gun slot.
- In Call of Duty Black Ops, the perk's icon on the neck of the bottle depicts a sombero, a mustache, and a bandolier. However in Call of Duty: Black Ops II, the perk's official icon is pictured.
- In Zombies mode, the perk depicts three M1911s, while in Cyborg Rising it depicts three G18s.
- In Black Ops 4, the perk icon depicts three Strifes.
- The backing track used for the Mule Kick jingle comes from a stock track entitled "One Man and His Horse". 
Call of Duty: Black Ops
- The player will not get 25 points for going prone in front of Mule Kick in Der Riese, unlike other Perk-a-Cola machines.
- On the Moon loading screen, there is a picture of a mule, and above it some text says Gun Mule, referencing to Mule Kick.
- The Mule Kick jingle isn't heard when the perk is purchased, unlike the other perks.
- None of the characters will state a quote after buying it on any map other than Moon.
Call of Duty: Black Ops II
- In Die Rise, all of the character's quotes when drinking Mule Kick is yelling "Mule Kick!".
- In Mob of the Dead, both Mule Kick and PhD Flopper are unobtainable Easter eggs. However, the player(s) can buy these Perks in the Grief map, Cell Block.
- Upon completion of Edward Richtofen's side of Mined Games, the player will receive a variant of Mule Kick that will allow the player to carry four weapons.
- When Mule Kick is bought in Cell Block, a phasing variant of its jingle can be heard. It sounds similar to the background whistle during the line "A hero in a tortured land."
- Mule Kick, along with Juggernog, Quick Revive, Speed Cola, Double Tap Root Beer, and Stamin-Up, has had its icon that appears in the HUD slightly altered between the release of Die Rise and Mob of the Dead for Call of Duty: Black Ops II. The background is slightly lighter now.
Call of Duty: Black Ops III
- In The Giant, none of the characters comment after buying the perk, despite commenting on it in every other map.
Call of Duty: Black Ops Cold War
- According to the nutrition facts on the Mule Kick can, one can of Mule Kick contains: 30 calories, 35g of fat, 90g of sodium, 250g of total carbs, 120g of sugars, and 200g of protein.
- According to the ingredients list on the Mule Kick can, one can of Mule Kick contains: beer, liquid cordite, cola nut, trigger finger extract, vitamin B-12 gauge. It also contains a warning stating that it "may contain hot lead".
- Whenever Mule Kick is purchased from its machine, the guns attached to it will start firing off and can kill nearby zombies.
- The guns fire in synchronization with its shortened jingle.