A character who undergoes some sort of fundamental change or transformation during a literary work is sometimes referred to as a "dynamic" character, and in this novel, Maxwell Kane most certainly fits that category. When the novel opens, Max is a sad, withdrawn young man, whose feelings of inadequacy are almost as large as the boy himself. His physical size is reminiscient of his father, who is in prison for killing his mother, but Max couldn't be more gentle or sensitive. When Kevin moves in next door one summer when they are in middle school, he brings a whole new dimenstion to Max's life. Because of Kevin, Max begins to understand and take part in the world of books, dreams, and imagination. Although Max has always resisted assistance in the public school setting, he proves to be no match for Kevin, who, although physically tiny due to a birth defect, is extremely intelligent, stubborn, even bossy, and issues directives to assist Max that Max complies with simply because Kevin doesn't really give him a choice. Kevin rides around town on Max's shoulders, sharing his ideas, and thus Freak the Mighty is born: Max's size allows Kevin to have a decent view of the world and "use" of Max's legs, while exposure to Kevin's intellect, imagination, and even sense of humor allow Max to quietly contemplate the idea that he might actually be worthy of someone's love, and perhaps he is not as stupid as he has always thought. At one point, Max observes of his struggles:
I never had a brain until Freak came along and let me borrow his for awhile, and that's the truth, the whole truth. The unvanquished truth, is how Freak would say it, and for a long time it was him who did the talking.
When school starts, Max is allowed to enroll in Kevin's advanced classes so the boys can share the same schedule, allowing Kevin to move through his day on Max's shoulders. Although Max is initially ridiculed in the advanced classes, Kevin puts a stop to that by announcing one day that they, together, are to be referred to as "Freak the Mighty". This amuses the class, and Kevin and Max achieve a bump in social status.
Because of Kevin, Max also learns what it means to laugh and have fun. Although one might wonder if a book with such serious subject matter might struggle to find opportunities for comic relief, Philbrick managed to do it, as in this scene where Max has gotten choked on his lunch and Freak is trying to assist:
"Expel the object!" Freak shouts. "Regurgitate, you big moron!" and he gives me another thump and I cough up this yucky mess, but I'm still laughing so hard my nose is running.
The most poignant example of Kevin's influence occurs after his death, when Max sits down to write a memoir of his time with his friend. This is the most dramatic of transformations, if one remembers the withdrawn, disinterested, demoralized Max of the novel's beginning, because, thanks to Kevin, the Max of the novel's ending is ready to explore his ideas and feelings in writing, on his own, free of the negative self-image that used to dominate his thoughts.
still doesn't explain IT ALL