The whirlybird is a great looking trick. It is basically a tantrum with a backside 360 with the rope passing over the head instead of doing a handle pass.
Starting this trick you must have a progressive edge and the speed to do a tantrum. Come in fast and flatting out as you approach the bottom of the wake. Remember to use the trip flip as you would with a tantrum.
As you are riding up the top of the wake start out same motion as a tantrum. Once you reach the top of the wake and have a solid pop, slightly turn your hips and back toward the boat to release some of the tension in the rope.
Handle must stay in tight, arm bent. Turn your head and shoulders away from the boat.
Snap your head and shoulders making sure to keep your body rotating so you can complete the spin.
As your board comes around you want to be spotting your landing, ready to stop your rotation. Starting to pull the handle toward you.
Pull the handle toward your mid-section to stop your momentum. Landing can be tricky if you do not have your rotation down. Overall equal to a tantrum landing if done correctly.