The Licker is a monster from the Resident Evil series. They are one such mutation experienced by zombies as part of the V-ACT process, depending on the variant of the t-Virus they were infected with. The mutations transform them into deadlier, more agile hunters.
The Licker came into existence at some point after the Crimson Head Prototype 1's creation, when V-ACT was underground research. By 1998 they were undergoing research at the Raccoon City Underground Laboratory as potential bio-weapons. The name "Licker" itself was first given to this creature by the officers at the Raccoon City Police Department, who encountered a number of them around the building during the Raccoon City Destruction Incident.
In the 21st century, the Licker was reexamined by Tricell, who modified the creatures with further viral infections to create a more powerful weapon. These mass-produced replicas, the Licker β, were also employed by rebels in the Eastern Slav Republic to fight against the armies of Svetlana Belikova, and were controlled using Plaga parasites.
Having completely lost all sense of sight, Lickers are unable to track prey visually; to compensate they have an overdeveloped sense of hearing, and will attack victims with their tongue and claws at the slightest sound.
When Lickers were introduced to the film, they were identified by the Red Queen as one of The Hive's earliest experiments. The production of the Lickers resulted in what the Red Queen described as an unstable development when the T-Virus was injected into living tissue.
After the special forces team had shut down the Red Queen's defenses, The Hive lost a considerable amount power, allowing one of the Lickers that was in its confinement to escape, lurking within The Hive. It eventually killed Spence Parks, who was earlier bitten by a zombie and tried to cure himself with the anti-virus. As it continued to consume Spence's flesh, the Red Queen reveals that when it consumes living DNA it mutates into a more enhanced form of Licker, describing it as a stronger, faster hunter.