Buck has several, including when he drills through the bedroom door at the party.
Buck's dialogue with his niece Maisy's principal, who has a hideous hairy mole on her chin:
Principal: I see a bad egg when I look at your niece. She is a twiddler, a dreamer, a sillyheart! She is a chatterbox, and frankly, I don't think she takes a thing in her life or her career as a student seriously. Buck: She's only six. Principal: That is not a valid excuse; I hear that every day and I dismiss it! Buck: I don't think I want to know a six-year-old who isn't a dreamer, or a sillyheart. And I sure don't want to know one who takes their student career seriously. I don't have a college degree. I don't even have a job. But I know a good kid when I see one. Because they're ALL good kids, until dried-out, brain-dead skags like you drag them down and convince them they're no good. You so much as scowl at my niece, or any other kid in this school, and I hear about it, and I'm coming looking for you! Take this quarter, go downtown, and have a rat gnaw that thing off your face! Good day to you, madam.
Almost as awesome as the epic speech, Buck punches a clown! Twice!
It's not so much the punching of said clown, but the reason for doing so. He realises that the clown who was hired for Miles' birthday party is drunk, and tells him to leave, and he only punches the clown when he gets hostile.
Clown: Hey, lemme tell you somethin' you low-life lyin' floor-flushin' sacka shi-!