War Cat

It is a good unit if you are using stealth or guerilla tactic, it is easy to produce if you have built the Big Cat Trainer wonder, since it only requires only one of the resources: copper ore, iron ore or obsidian; and a Barrack.

It hides nationality and can attack without declaring the war, so it's ideal to attack your neighbors economy at times of peace.

It can be upgraded to Guard Cat: a stronger and stealthier version of itself.