|Theo Merton Jr.|
|Name||Theodore Merton Jr.|
|Also Know As||Theo Merton Jr.|
|Birthday||Tuesday June 19, 2001|
|Residence||The Merton House|
|About friendship, interests and family|
|Affiliations||Port Doover Elementary|
McGal & Spritz
|Love Interests||Gwyn Sanders|
|Parents||Theo Merton Sr. (single father)|
|Others||Leo Wexler-Moltmann (great great grandfather)|
|Appearance and Voice actor|
|First episode||Dodge This|
|Last episode||Part 2 of a Balanced Breakfast|
|Voiced by:||Kevin Duhaney|
Theo is super smart and cautious. Deep down, he would have liked to like Nick. However, unlike his friend, Theo analyzed all possible options before making a decision. He always has an answer and a scientific explanation of what happens both in the Loop.
He is a African American boy with thin body and has short curly brown hair and he wears glasses. He also wears a green shirt, beige jeans and red shoes. He is slightly taller than Luc. Compared to most of the other characters, he has darker skin.
Theo is a pessimistic, phlegmatic boy who is also very intelligent and nerdy. He is not always on board with Luc's ideas because he doesn't just rush through things. He knows the logical explanation for pretty much everything that goes on in the loop and knows everything about the day they're trapped in backwards and forwards.
Luc and Theo are best friends and the only two with knowledge of the loop. They have fun, get into trouble, and take advantage of the loop together. Theo is the voice of reason to Luc, though it usually takes a while before he realizes when he's taking it too far.
Theo loves Gwyn with all his heart, but she does not return the favor. Gwyn finds Theo repulsive and avoids him by all means. To add insult to injury, she's also madly in love with his best friend, Luc.
Jesse bullies Theo every day (aside from just the repeating Monday), by putting him in a wooden box and farting into it.
- Theo has a single father, named Theo Merton Sr., who only appeared in the episode "Badmerton to the Bone"
- He and Luc's phones match their respective shirt colors. Theo's phone and shirt are green.
- His name is Theo Zweistein in the German dub.
- In "All Things being Sequel" he's erroneously called Theo Matthews.