They wander around your main command center looking cute and sometimes make noises to vie for your attention. Don't worry, they will move out of the way of any buildings being built. While they cannot be interacted with directly (you can't click them, your opponent can't kill them, etc.), or provide any impact to your gameplay, they may give you a morale boost! 

Example: Chicken Supporter Pet

This pet is only available as part of the Deluxe or Ultimate Early Access Packs