Mary is unable to move fast enough, however, as Jim's father unintentionally blocks her access to the box. She's too big to go under him, and not nearly agile enough to go over him, and he's too panic-stricken to move.
Soon, his growth causes him to crash through the roof of the house, quickly becoming one hundred percent a brachiosaurus - which causes his human mind to panic. He stomps down the street, galloping with thundering footsteps that crack the cement, leaving behind two bewildered female brachiosaur-people and a male of the same species who is far too busy pleasuring himself to notice what just happened.