In The Zone

Dominant Species

Get Programmer's Dog
You must press the tilde key (~) to access the cheat console then press ENTER and type "spawn cisco 1". Now you can use one of the programmer's dog as a creature in the game

Invincibile Units
For invincible units, select a group of units then press the tilde (~) key to access the console then press ENTER and type "armorofgod 10000".