Separate the two circles slightly, and tightly knot a piece of yarn at the middle, leaving the ends long, to act as legs. This is a good time to cut the pipe cleaner to the size you want the flamingo neck to be. Slide a piece of pipe cleaner in the hole inside the pompom.
Remove the cardboard circles carefully and trim the pompom if necessary. Model the neck of the flamingo with your hands and you’re done!