Ok, this is the best I can do...
http://www.eli0s.com/Tests/BarkingHeads.capx
I removed the pin behavior as it doesn't inherit the mirroring of its parent, instead I used the every tick set position to an image point and mirroring actions for the heads.
The enemies move randomly left and right with the platform behavior (if you only need them to do small movements that do not jump or follow uneven ground, then the Platform is an overkill) and when the player is in range they follow him/her, barking (hopefully) facing the right way...
Use the arrow keys to move the player around (default controls).