Licker

What seem like quite a comical name for a monster, there's nothing funny about these once you encounter them for the first time. The name comes from its incredibly long tongue, and it can use this to whip at you from a distance while it crawls around on all fours on the floor, walls and ceiling to avoid your bullets. These creatures supposedly started off as regular Zombies, but further mutation caused their muscle mass to increase and literally burst through their skin, and their fingernails to transform into full-on claws.

These enemies to have one weakness, and that is they are blind. So if you walk rather than run before they've realised you're in the room, it's possible to sneak up on them and get a surprise attack in. They are best tackled with either the Shotgun or the Grenade Launcher.