Theodore "Teddy" Bhaer is the three-year-old younger son of Josephine "Jo" Bhaer (née March) and Professor Friedrich Bhaer, and brother to Robin "Rob" Bhaer. His family home is Plumfield, the school founded by his parents.

Teddy physically resembles his father but possesses his mother's distinctive grey eyes. He experiences a typical early childhood immersed in Plumfield's supportive, educational atmosphere, surrounded by students, extended family like cousins, and orphans cared for by his parents.

His daily routine involves participating in school activities alongside the other children. This includes outdoor adventures and simple childhood pursuits: joining strawberry picking expeditions, venturing into the wonders and perceived dangers of the nearby dark forest, and sharing in lighthearted mischief like a "big war in pajamas."

Teddy forms bonds with older students and residents. A significant connection is his trusting relationship with Dan Kean, a rebellious adolescent taken in by the Bhaers; the pair share a secret, highlighting Teddy's approachable and affectionate nature.

Teddy participates in seasonal events and celebrations organized by the Plumfield community, such as kite flying. His presence contributes to depicting Plumfield as a vibrant, family-centered educational environment.