 Rex Britten , portrayed by Dylan Minnette , is Michael 's son who is featured in Michael 's " green reality " . Green is Rex 's favorite color . He is a teenage school student . Outside of school , Rex claims he is going to the beach , although he is really going to his best friend Cole 's house to work on a motorbike with him . Like Hannah , Rex is also very emotional , and often gets angry , due to Hannah 's death in the crash . He kept a tennis racket to remain , and make him deal with Hannah 's death . However , Cole accidentally broke it , Rex fights with him because of this . He later apologizes to him . He hates " cereal and soda night " because Michael doesn not cook " actual food " for dinner . Rex has an aunt named Carol , who is mentioned in " Two Birds " , in Michael 's " green reality " . She wants to spend more time with Rex since the crash . 
