Gecko (Fallout 2)

Geckos are creatures found in New California of 2241.

Biology
The golden gecko is the more beautiful, but also more deadly than the little gecko. Fire geckos can breathe fire thanks to unknown toxic substances being combined in their gut and are immune to fire. Little- and fire geckos can be skinned, if you have the Gecko Skinning perk.

Gameplay attributes
Little geckos have horrible detection AI, and it is often possible for the player to walk right in front of them and not be noticed. This makes it easy to get inside attack range without being caught. While it has been suggested that little geckos attack only when provoked, this is not true.

Silver gecko
Silver geckos, called little geckos in game, are the easiest of the geckos to kill. They appear quite early in the game. (already in the Fallout 2 quest - Rescue Nagor's dog, Smoke, from the wilds., where they roam the Arroyo Hunting Grounds).

Golden gecko
As stated by Smiley, the Trapper from the quest Rescue Smiley the Trapper., golden geckos can be found near toxic waste, which they seem to lick up. Though it's not said explicitly, obviously there seems to be a connection between the toxic/radioactive waste and the golden geckos. It can be assumed that exposure to some kind of toxic/radioactive material turns a normal gecko into a golden one.

Fire gecko
The fire gecko is the most deadly kind of gecko in Fallout 2. They appear mostly in late game and, as indicated by their name, can breathe fire thanks to unknown toxic substances being combined in their gut. They are quite hard to kill and as opposed to both other forms can not be skinned, as their hides are far too mangy and burnt to be worth anything. Not surprisingly, they are immune to fire damage.

Appearances in games
Geckos appear in Fallout 2 and Fallout: New Vegas.