Lethians

Lethians are a variant of Wylebeasts.

Description
Originally residents of Oakmont, a pathogen has corrupted and mutated them into humanoid wylebeasts that can vertically split their heads to project blobs full of bacteria at the player. Lethians can be dangerous up close, and should usually be attacked at range, preferably with shots to the head.Westerbrook's Guide, p. 2"Research on Oakmont's Post-Flood Fauna, by Prof. E. Westerbrook, Oakmont University""Part two : Lethians""The Lethians' forms resemble humans. After numerous autopsies, I can state with confidence that there are multiple pathogens which can cause these mutations in human victims. Their bulb-like colonies act like additional hearts, ensuring the flow of lymphatic fluids, filled with bacteria. The fluid is gathered in the former human's stomach, and may then be expelled by the Lethians with an immense force. The less studied Immortals have rapid regeneration, and I have received reports about Wraiths that 'disappeared'."

Variations
In addition to the standard Lethian, there are two special forms:

Wraith - Lethian that can become invisible; only detectable by distortions in the air created when they move.

Immortals - Powerful Lethians that can regenerate their own health. It is advised to continue shooting them while they're down.