PhD Flopper is a Perk-a-Cola Machine that appears in the Call of Duty: Black OpsNazi Zombies maps Ascension, Call of the Dead, Shangri-La, Moon, and secretly on Die Rise and Mob of the Dead, as well as in Cell Block and Origins from the WunderFizz Machine. After the player buys the perk, all damage that the player could cause to themselves by explosives and fall damage is nullified. For example, a player could cook a grenade and let it explode in their hands, not harming the player but still inflicting damage on zombies. It completely removes splash damage, making the Ray Gun, Mustang & Sally, Matryoshka Dolls or any explosive good for getting out of tight situations, and adds a miniature explosion whenever a player with the perk dives to prone. However, the explosion only occurs if you dive high enough that you would normally recieve fall damage. It instantly kills all zombies within the small radius of the explosion in the earlier rounds and makes crawlers in the later rounds. Any kill you get from the explosion is only 50 points like all the other explosives.
(PhD) Night-time scene. (PhD) The streets are mean. (PhD) The things I have seen. (PhD), the good, the bad, and the in-between. When you dive to prone, you are surely gonna own, PhD (Flopper)! When you dive to prone, it's gonna shake ya to the bone, all the zombies gonna groan, 'cause of PhD! (PHD) The feelin's growing strong. (PhD) So right that it feels wrong. (PhD) Like the chorus of a song. (PhD) Not short but not too long. Slap your body to the floor, everybody needs some more, of your lovin', your explosive lovin'. When you dive to prone, it's gonna shake ya to the bone, all the zombies gonna groan, cause of PhD! (PhD) (Flopper)! Damn straight.
PhD Flopper will protect you from any fall, for example, the lighthouse in Call of the Dead.
PhD Flopper can be a useful perk for when you're out of ammo.
It is not actually a vending machine. Instead, it fills a cup placed under the nozzle.
According to the players, PhD Flopper taste like Prunes and Chemicals.
Takeo is allergic to prunes, making this his least favorite perk
In the Die Rise map on Black Ops 2, PhD Flopper is secretly located on the 3rd level when going down the broken cargo elevator (at the beginning). It is physicaly impossible for the player to get to it because there is an invisible barrier around it. It is easier to see this perk machine when going into theater mode going on free camera.
PhD Flopper makes it return into Black Ops 2 Zombies, in the map Mob of the Dead. As well as appearing by the docks, it is available for purchase in Cell Block , Grief for 2000 points.