Buster Moon is an anthropomorphic koala. He has gray fur with white fur inside of his ears. He wears a white button-down shirt with a red bow tie covered by a blue suit jacket. He also wears blue pants with a black belt and brown shoes.
Buster Moon is truly the optimist, Buster doesn't know when to quit, and believes in the concept that when you've hit rock-bottom, the only way left to go is up.
Buster has a sincere love for show biz, especially theater, after attending his first theatrical performance (his dreams of becoming the first koala bear in space were suddenly toast) when he was only six years old and was inspired to one day own his own theater and make his career in show business as a successful theater producer. He loves his theater and won't give it up without a fight, not only because of his love for theater but because his father worked so hard and for so long to help Buster buy the theater in order to fulfill his son's dream, and Buster keeps the bucket his father used in his car-washing business to make that dream a reality as a cherished memento.
Even when all odds seem to be against him, Buster looks for a silver lining in every cloud, no matter how unlikely or ridiculous, gives it his all, but oftentimes his refusal to quit comes back to haunt him.
His determination to save his theater from being shut down drives Buster to do anything and everything to do so, such as going to extremes to avoid dealing with the bank, illegally siphoning power from a next-door business after his theater's electric bill shuts the power down, and stealing gallons of water from a water tower to set up a unique stage, lying to his contestants about the $100,000 prize money (which was supposed to be only $1,000), etc.
He is cheeky, opportunistic, and even a little pushy.
When everything goes wrong and literally comes crashing down, Buster finally breaks and gives up, is unresponsive to his singers' support and encouragement, and fully prepared to accept a fate of car-washing until he hears and is inspired by Meena's beautiful singing to take one last shot.
He rallies the troops, they throw together a workable open-air theater, and perform for free, each of his singers' pulling off spectacular performances that redeems Buster in the eyes of the public as well as Nana Noodleman, the theater actress who was partly responsible for inspiring Buster to love theater, that she buys back the theater property and restores it, allowing Buster to hold a grand re-opening and truly make his career as a successful theater producer.
Buster Moon realized the dream of owning the theater when he attended the show "Epiphany" with his father, but the place has fallen on hard times with nobody coming for shows anymore. Even though his best friend, a Suffolk sheep named Eddie (John C. Reilly), doesn’t think it’s a great idea, he decides to put on the world’s greatest singing competition as a final effort to restore the theater's popularity.
He scrapes together $1,000 for the winner, but thanks to Buster’s doddering old lizard assistant, fliers go out proclaiming a $100,000 prize, causing a stir in the animal world. And as Buster fights for his theater’s relevance, five characters become the top talent in the competition all of whom are ultimately trying to define or redefine or find themselves through music and performance.
“My next show is gonna be, drumroll please: a singing competition!”
“Everyone. Just think, your neighbor, the-the-the grocery store manager, that-that-that-that chicken, right there. Everyone in the city gets a shot at being a star live on my stage!”
“Real talent from real life. That's what audiences want and I'm gonna give it to them!”
“And cue the crazy old lizard.”
–Buster Moon, moments before Miss Crawly enters his office
“I do? Holy moly, I really do.”
–Buster Moon, seeing a group of angry animals outside his office, also when he sees a long line of animals waiting to audition
“Yes, I was saying that you are in... oh jeez, this is gonna drive me nuts. Johnny, get back here. You're in. Thank you, Daniel. Goodbye!”
–Buster Moon, quickly realizing the burden of having to use a megaphone to communicate with Daniel, dismisses him from the competition and selects Johnny instead.
“Hahaha, yaaaa! Gonna spice things up on stage!”
–Buster Moon, moments after pairing Gunter up with Rosita as her dance partner
“I have this bucket because it belonged to my father. Every day for 30 years, he'd worked his tail off washing cars, just so I can buy this place. Every day, Eddie. Just for me.”
–Buster Moon, telling Eddie about his father's bucket
“You know what's great about hitting rock bottom, Eddie? There's only one way left to go, and that's UP!”
“Are you wearing a speedo, Eddie?”
–Buster Moon, to Eddie
“What's not to like? You're a female and you're a teenager. This song is made for you!"”
He lives in his theater, sleeping in his desk drawer.
He is at least 36 years old. In the first scene of Sing, Buster recalls being 6 years old while watching his first theater performance. From that moment on, his father worked as a car washer for 30 years to buy his son the theater.
Prior to wanting to have his own theater, Buster wanted to be the first koala in space.