After I completed the Double Ball with a Tail assignment, I used the exact same principle and applied it to a pair of balls jumping from one side of the field across to the other.
I began with the first drawing of the balls at the high point in the middle.
And then the low point key #7.
I then added some recovery and an anticipation before jumping back up to the high point in the middle again.
Recovery...
Anticipation...
Push...
High point.
Here's what it looks like as a pencil test with the mirror side completed as well.
I then went back and added on the tail, following the path of action of the balls the same way I did with the Perpetual Double Ball Bounce With a Tail assignment.
Then I went back and added on some legs.
And finally I went back and added the details to make the shapes into a cat.
See also the Descending Energy Cat Jump demo.