To set a unique profile picture that stands out from the default options, all you need is to connect your game to your Facebook account. Once connected, simply tap your Player name from the Main Flock screen, then tap your current avatar.
You'll notice a blank picture at the top left corner of the avatar list. Select this option, and your in-game avatar will synchronize with your Facebook profile picture. Just remember to save your changes by tapping "Save changes" after you've made your choice!
Just remember, your profile picture should follow our Safety Guidelines. If it doesn't, our moderation team will change it back to an in-game picture. Also, keep in mind that you can only use your Facebook profile picture, not any other external images.