Some exercises are to learn gymnastics movements. It can be advanced ab exercise and it may not be suitable for bigger people. But if you want to try something new and feel the burn at the end, these are perfect for you.
Single Leg Knee tuck on swissball

Place both feet on the ball initially, then tuck one of the knees to the chest up in the air, hold the position, then tuck the other knee towards the chest. Make sure one leg is up in the air all the time. You can try 10 repetitions for each.
Press Handstand practice on swissball

If you want to learn press to handstand, this will help you learn the movement. If not, but still you can try this ab exercise.
Start with both feet on the ball, drag the feet to you, creating a “pike position”. If you are serious about learning how to do press to handstand, the key is to get the hip higher. Once you can get your hip right above your wrist, you may be able to go to the next step for the press to handstand.
Press to handstand on the swissball
Swinging to L-sit

Start with l-sit position, swing back to tuck planche position, then swing back to l-sit position. Try this for 10 – 15 repetition. As you are doing over and over, you will be able to do v-sit hold position. This is much harder and requires active flexibility also.

Check other ab exercises I learned by doing gymnastics