Most of the time I sit and figure out what pose I'm after by doing variations on the pose. Then there are those times that the pose comes to you pretty much all there! This is one of those.
I had an incling of an image in my head of Antman vs and Ant-eater. Antmans pose pretty much dropped right out of the pencil as my second option.
My two thoughts had been just before the leap and swing and then this one of the mid-swing. Mid-swing won by a mile and was just way more involving and dynamic.
One of the great things I enjoy when looking for a pose, even in an instance where you get a good one off the cuff is looking where to tweak it in order to get the clearest outline/sillhouette from it. Here in the sketch you can see the camera left leg has been moved. Originally I was looking at having it more towards the camera/viewer but the killed the movement. I drew the arm up by his face as part of the swing first but started to wonder if an extended arm might give balance to the pose and quickly realised he needed to look coiled and that the straight arm tipped his centre of gravity the wrong way for the eye movement through the image.