Preston:

Preston is Sheldon's best friend. He wears glasses and is very intelligent. Preston loves learning and discovering new things. Because of his curiosity, Preston typically goes a little deeper into a subject than most would like, but his friends do not mind.

The Twins Timothy & Tammy:

Timothy is of Latin descent and he speaks English and Spanish. He and Sheldon are very close friends and live in the same neighborhood. Timothy is very athletic. He is often called upon in situations that require his athleticism. He loves animals and his friends turn to him when they have questions about wildlife.

Tammy, like her brother, is of Latin descent and she speaks English and Spanish. Tammy loves to read and teach other children about the new things she has learned. Her favorite subject is math.