When a mysterious stranger arrives from the future with a dire warning, Leo is forced to rise and lead his brothers, Raph, Donnie, and Mikey in a fight to save the world from a terrifying alien species... the Krang.

Casey is polite and kind, He is also level-headed and approaches dangerous situations with care. Casey is unafraid of being quite direct and honest when upset.

Leo is prone to make jokes and sarcastic remarks, often during inappropriate times, which can sometimes leave his brothers annoyed and frustrated towards him.

Raph is exuberant, and passionate, known for his valiant attitude and impulsive streak. Raphael is often impulsive, Raphael is the former leader, not taking account for whenever his brothers would come up with plans other than his own.

Donatello is autistic, as confirmed by the creator, and demonstrates low Emotional Intelligence. This means that he struggles with understanding certain basic human emotions, in reacting appropriately to those emotions in others, and in controlling and managing his own emotions.

Mikey is playful and lighthearted. He is intuitive, able to adopt new skills quickly, Mikey is very creative at heart.