From The TimeSplitters Wiki

Sewer Zombie
Unlocked by	TS2: Challenge > Behead the Undead > Fight Off the Living Dead with Silver or Better TS3: Get Silver in all Challenges
Species	Zombie
Size	Normal
Accuracy	5
Agility	2
Stamina	10
Fire Proof	?
Shock Proof	?
Default AI	4 stars
Native TimeZone	1867
First Appearance	TS2 Story Mode
Relations	Crypt Zombie, Jacque de la Morte
Games	TS2, TSFP

Sewer Zombie is, as its name suggests, a Zombie. He is resurrected by Jacque de la Morte at Notre Dame. He is the most common enemy in the level.

TS1 Gesture	N/A	TSFP Gesture	Makes some strange bubbling noises and falls to ground
TS2 Gallery	The fetid depths of the Parisian sewers are the final resting place of many unfortunate murder victims and diseased beggars. The dark magic suffusing Notre Dame has reanimated their half-rotted bodies.	TSFP Gallery	When he's not bobbing in the Parisian sewers he's equally at home floating down a Venetian canal.

Appearence and Movement

The sewer zombie is quite ugly. It is covered in sewer slime, thus giving it its name. Its clothes are decaying, giving them brown and green colors. Additionlly, part of their rib cage is exposed.
In Story mode, Sewer Zombies have a characteristic zombie limp in their movements. They commonly fall over as they walk, further showing their "zombie heritage". Being zombies, they can live even if you shoot their heads and arms off. In the case you shoot their arms of, they will start biting you if they get close enough.

Attacks

Sewer zombies have a variety of attacks. The most common one is getting close to you and punching you. However, you can shoot of their arms, in which case they bite instead of punch. On normal difficulty, some sewer zombies spit a green acid-like substance at you.