"The corrupt body of this infected person has swollen to an enormous size. Its thick skin makes it almost invulnerable to low-caliber weapons."
An Infected Giant swipes back and forth in front of himself with his huge arms. This AoE attack can kill dozens of Rangers in a single swipe.
The Infected Giant only appears at difficulty "Medium Population (Challenging)" and higher.
In the campaign, their health varies from 4000 to 20000 depending on the difficulty.