This character has a unique design and, while I was setting this, what I had an issue with was the joint placement of Jaw. The reason is that, once I put the joint to the location which is based on human anatomy, in terms of the deformation of this character, I could not get the proper deformation that I want. Thus, I tried to do several tests in two big categories, the first category is aimed at the placement of the joint and, the second thing is the combination fixing of skin weight and joint placement to solve this issue. As you can see at the bottom of the images, I chose the bottom of the right corner way. The reason is that even the character looks like a unique style though, I should follow the principle of human anatomy and consider character design at the same time. So, I tried to research and find how to move the jaw's movement and what is the best deformation for this cartoony character. Even though I tried to do a manual setup for global joints of the face, what I learned is that joint placement is a very important initial process, sometimes it can be changed depending on the character's design. Also, I just keep in mind that painting skin weight is another important key point to achieve a good quality of the rigging.