If you uncheck the Inverse Kinematics it is easier to make figures jump. Shape Shifting is possible and fairly easy. Just keyframe the 2 different states and make sure there is enough frames between them and voila: shape shifting. Of course you will have to scale his arms/hands as you please. Also you may want to look for bvh files, there are some free ones around, not long ago there was a thread here with a lot of links. Try searching for bvh. bvh files are motion capture files that can be applied to Poser figures with amazing results. Oh and: Welcome to Renderosity. A place almost more addictive than Poser itself ;o)

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You just can't put the words "Poserites" and "happy" in the same sentence - didn't you know that? LaurieA
  Using Poser since 2002. Currently at Version 11.1 - Win 10.