The key features of a sidekick character are that they are usually the protagonist's sidekick and their appearance is not as important as the protagonist's. They are often used to represent a specific group in society, such as children or people from a lower social class. A sidekick is a character who supports the protagonist in their adventures. They often provide comic relief and offer advice to help with problems that the protagonist is facing. However, they do not have any major significance in the story and are often used to represent a certain group of people in society, such as children or people from a lower social class.