Human flag? The dragonfly?
Try to incorporate some core workouts followed by some back and bicep exercises that should help to perform the human flag
U need to train your core like crazy for that. You need to train shoulders and arms as well. My advice get to a pull up bar hold yourself up so your eye level with the bar then raise your legs on hold that pose. Of course this is one of many things to do. Good luck.
I haven't tried it but it seems worth checking out: http://mikwend.hubpages.com/hub/human-flag-training-and-tips
Good luck man!