Quote - This is not easy to do because adding a bone to an existing figure can cause problems with the joint parameters and other things associated with the figure.

Creating Morph Targets (MTs) for a figure is a better way to go and, also, allows for more variables.

The reason why I asked that question is the bone system we tried to build in this tutorial can become the bone system for the tail.  If I can attached it to the hip, it will be perfect.  Too bad, it seems that we can't.

Quote - Yes, rescaling body parts can be tricky because it can affect the joint parameters which are difficult to adjust properly.

One possibility is to export the figure as an object, make the modifications to the geometry in an external (outside of Poser) modeling program, e.g., Carrara, et al.  Then import the modified figure back into Poser and create the required bone structure for the new figure.

Do you have any tutorial about the joint parameters?