From The TimeSplitters Wiki

Green Zombie
Unlocked by	Challenge > 1-B Putrid Punchout
Species	Zombie
Size	Normal
Accuracy	N/A
Agility	N/A
Stamina	N/A
Fire Proof	N/A
Shock Proof	N/A
Default AI	N/A
Native TimeZone	1965
First Appearance	TS1 Story Mode
Relations	Brown Zombie
Games	TS1

Green Zombie is a generic zombie, who doesn't look green contrary to his name. Brown Zombie shares his characteristics and appearance except he is inversely arranged (brown zombie's eye is on the left, green zombie's is on the right).

TS1 Gesture	Is suprised the player has picked him, then gets ready.	TSFP Gesture	N/A
TS2 Gallery	N/A	TSFP Gallery	N/A