Besides drawing your own figures (which you might be able to do from pictures online such as the one below) you can also download figure packs directly from websites such as Droidz.org which has a huge database of stick related add-ons, from characters, to vehicles to weapons: http://droidz.org/stickmain/
Sticksforfree also includes some downloadable character designs and has a useful selection of Youtube tutorials which have been compiled to help with stick design and animation, check them out here: http://sticksforfree.weebly.com/tutorial.html
There is also this video on Youtube which links to the 'ultimate pivot download pack' filled with characters as shown and can be found in the video description. Not only is this useful to see the character pack but also shows you how to import your figures into a new pivot animation:
