The Pseudogiant resembles a massive, drop-shaped abdomen with a pair of disproportionately large limbs. The limbs are arms and legs at the same time. The creature uses them to move around and grab its victims. An adult Pseudogiant can weigh up to two tons and stand 2 meters tall. Their clumsy appearance might be deceiving, since they can move very rapidly if needed. Their muscles are exceptionally powerful and their bones are as hard as steel. The creature's brain is protected by a sturdy (up to 10 centimeters thick) skull, while many complex functions are controlled by the spinal medulla. Another astonishing feature of the beast is its ability to create local shock waves, which damage all living things in the vicinity.
- Pseudogiants are very unique in the Zone's fauna, as they seem to be heavily-mutated humans. Pseudogiants are incredibly tough enemies which can withstand large amounts of damage before being killed, and are very dangerous to unprepared stalkers due to their ability to deal a large amount of damage when it attacks.
- The Pseudogiant uses four attacks: a headbutt; a swing/grab with one of its muscled arms; a surprisingly effective stab from its smaller, clawed arms; and a ground pound that creates a damaging impact shockwave. The first three attacks can be avoided by being out of range, and the last area-of-effect attack can be avoided by jumping just before it pounds the ground, which can be a bit tricky.