I had the best luck last month at Animal Kingdom with new characters for my vest. I now have Flik, Dug, and Russell for my fun.
It was a pleasure to interact with each of them and Russell was very impressed with my vest and how prepared I was with everything I carry in thee pockets (sunscreen, aspirin, band aids, flashlight, you get the idea).
Be aware that some characters like King Louie and Baloo cannot sign but are happy to have their picture taken with you.
Enjoy and see what new ones you can find, I once found Jiminy Cricket there! Enjoy!!