I rarely hear the actual name for this pose pop up, but the move itself is very common.
In here I’ll also describe how to do hocks on top, since that is how you pretty much have to start it off. Begin seated on the hoop. Hold on to the top bar with your hands. If you are very strong, pike up and hook your knees on top. This can be more difficult than piking from the floor since you can’t cheat and jump. So if you can’t do it yet, don’t worry. As an alternative, you can get up by leaning back and placing one foot on the top bar, then the other. Use the feet to lift and turn yourself, and then hook your knees on top.
Once you’re in hocks on top, place your hands on the bottom bar. Push it in front of your until your arms are straight. It looks prettier if you arch your back and look up. You can also push the bar in the other direction.
To come down, you can exit in the reverse of how you came in, through pike. Use pull up strength to end up in a seated pose (if you don’t have enough, you might end up hanging by your arms). Another option is to move both knees on one side of the carabiner, and then slide down the side of the hoop into cradle.
A good demonstration is on the Circus Dictionary, and below is a photo of me doing it a while ago.