Final answer:
The character described does not match any of the provided text references, as none include a twelve-year-old with darker skin. More information is needed to identify a literary character that fits the student's description.
Step-by-step explanation:
The description of a character with darker skin, twelve years old, self conscious, and a good guy, does not directly align with the provided reference texts. These characters, while varied, do not include a character that is both twelve years old and described with darker skin. However, it is important to recognize that character development in literature often involves changes in perceptions, as indicated through the example of a character initially thought to be a 'bad guy' turning out to be a 'good guy'. This demonstrates the complexity of characters and may signify the dangers of stereotyping based on initial appearances or actions.
In order to address the question effectively, it would be necessary to have a specific literary work or character in mind that fits the description. Unfortunately, with the references provided, we do not have enough information to conclusively identify a character that meets all the criteria mentioned by the student.