Jeff is a Combine Hazmat Worker who has mutated into a unique kind of zombie with a head resembling that of a monstrous Venus flytrap. His right arm has swelled up into a colossal, muscular limb, and several large fungal growths have overtaken his back which continually release spores into the air. Jeff is not a classic Zombie in that he is not the host of a Headcrab but rather was apparently infected by exposure to spore clouds. Although he is blind, Jeff possesses a sharp sense of hearing and can be distracted using the impact sounds of thrown objects, particularly the great number of vodka bottles scattered around the Distillery. As he still retains the Combine authorization of a Hazmat Worker, he can freely travel through Force Fields. He is incredibly powerful, being immune to all gunfire which only sends him into a state of rage, and can easily tear apart any being he gets his hands on. Upon catching a victim, he vomits a massive amount of what appears to be corrosive acid on them before killing them with brute force.
Alyx Vance is first introduced to the creature by Larry while she's passing through the Distillery. Larry instructs her on how to use sounds to predictably lure Jeff around and to cover her mouth so as not to cough from the gases coming from his spewing spores or the many other Xen fungal growths dotted around the building. Alyx attempts to lock Jeff in a fridge and sneak onto an elevator to safely travel to another floor, but after several mishaps, she ends up bringing him along on the ride. Jeff follows her to a storage room where she searches for three batteries to power up a Combine tunnel seal. At the end of the chapter, Alyx manages to trap Jeff inside a trash compactor, and the player is given a choice to either activate the machine and fatally crush him or to spare him and leave him trapped.
|Stay close to Jeff for 10 seconds (but not too close).|
|Hold Your Liquor|
|Catch a bottle falling out of a cupboard before it breaks and alerts Jeff.|
|Escape the distillery without killing Jeff.|
Behind the scenes
The idea of a blind, unkillable enemy came up very early in the game's development. A model of a regular zombie was used for the initial tests, earning Jeff the "Blind Zombie" nickname by which he is referred to internally, while the level itself was just a large box he wandered around while the player had to avoid him. Even so, the concept proved to be largely successful with the playtesters. Several designs were made for the Blind Zombie's appearance; for a long time it was a Combine robot with damaged face to make its blindness apparent. The developers eventually decided on a unique appearance, not affiliated with the Combine or any of the game's creatures, as a way to signal to the player that this enemy requires a different approach.
Early puzzle tests featured closer interactions with Jeff himself, like hanging objects on him or stealing a keycard from his pocket. The mouth covering gesture was added as a response to the playtesters doing so instinctively to avoid coughing from the spores released by Xen fungi that make Alyx cough.
After Jeff is crushed in the trash compactor, his corpse will spew one last cloud of spores if the player gets close enough to examine it.
Smashing a Headcrab to death in the elevator.
Jeff in The Final Hours of Half-Life: Alyx.