Final answer:
The figurative language in the phrase is personification, where Bud's stomach is given human-like abilities to control his mouth, expressing his intense hunger.
Step-by-step explanation:
In the statement, “Before my brain could stop it my stomach made my mouth shout out,” the figurative language used is personification. Personification is a form of figurative language where human qualities are attributed to objects or abstract concepts. The student's stomach is given the human ability to make the mouth shout, which is not something a stomach can literally do. This personification effectively conveys Bud's hunger and involuntary reaction, adding depth to the narrative by illustrating how intense feelings can seem to take on a life of their own.