Mr. Big had humble beginnings. As a child, he was raised by his grandmother, whom he loved and respected dearly. Mr. Big's grandmother, or "Grandmama", was responsible for teaching Big the values of respect, determination, and family. His family would grow over time, as he would eventually find love, and have a daughter, whom he cherishes above all else, declaring her as "the light of his life".
Mr. Big is a self-made millionaire, having started with a few tuxedo shops in Little Rodentia, and eventually climbing up the financial ladder by becoming the owner of several successful legitimate businesses throughout Zootopia, such as the Tundratown limo-service.
Mr. Big and Nick Wilde also have a history. At some point prior to the film, they developed a partnership, and one that Mr. Big valued, as he saw Nick as family, having invited the latter into his home. Nick was even offered cannoli made by Grandmama. However, this partnership was short lived, as Nick sold Mr. Big a very expensive wool rug made from the fur of a skunk's butt. Mr. Big developed a sincere grudge against Nick following this event, as it disrespected the former and his grandmother, who passed away shortly after Nick's betrayal. She was buried in the skunk-butt rug, per Mr. Big's demands.
Mr. Big is often surrounded by a mafia of burly, well-dressed polar bears, who act as his bodyguards and henchmen; all of which are usually silent, stoic, and extremely loyal to their superior. His most trusted of the group is Koslov, the largest and most intimidating of the mafia, who also acts as Mr. Big's personal escort and mode of transportation.
Mr. Big carries himself with a strong sense of class and dignity. In spite of being a crime boss, he is not inherently villainous, and prefers to establish healthy relationships with business partners, rather than intimidating someone to work as his accomplice. He values family, and is capable of seeing his acquaintances and employees, such as Mr. Otterton and Nick Wilde, initially, as family themselves, going as far as to inviting them into his home, and providing homemade food and other luxuries in gratitude for their services, showing himself to be highly hospitable and respectful.
This is also seen with his blood relatives, such as Fru Fru, whom he admires dearly. Unlike her father, Fru Fru is extremely social and sweet, and disapproves of her father's criminal activities. Nevertheless, she has been shown to return his affections, and the two share a healthy relationship. Those who treat Fru Fru well, in spite of their past actions, immediately becomes an individual worthy of kindness in the eyes of Mr. Big, and he will gladly show his appreciation in a grand manner.
Should he be crossed after establishing a partnership, however, Mr. Big becomes a deadly adversary. He commands respect, and when feeling disrespected, no matter the circumstances, his first method of action is to kill whomever opposes him. This balance of firm and fair has solidified his status and reputation in Zootopia's underworld.
Role in the film
During an investigation to find Emmitt Otterton, Judy and Nick track down the limousine Otterton was last seen in before his disappearance. What they discover is a ransacked car, and that it belongs to Mr. Big. Big's polar bear henchmen, Raymond and Kevin, find Nick and Judy and take them to their boss' estate. Mr. Big confronts Nick on the latter's audacity to arrive unannounced on the day that his daughter is to be married, and further laments his feelings of betrayal and disrespect, regarding Wilde's rug scam. Nick tries to talk his way out of the situation, but is interrupted by Judy, who places Mr. Big under police suspicion, believing him to be a culprit in Otterton's disappearance. Offended, Mr. Big sentences Nick and Judy to death via cryonic torture, but this is stopped by the arrival of Fru Fru, who scolds her father for breaking his promise not to "ice" anyone on the day of her wedding. Fru Fru then notices Judy, and explains that the rabbit saved her from being crushed by a giant donut while shopping in Little Rodentia. Mr. Big immediately releases Judy and Nick, feeling grateful for Judy's services to his daughter.
To thank the two, Mr. Big invites them to Fru Fru's wedding, where he explains what he knows about Otterton, who turns out to be Mr. Big's personal florist wanting to discuss something urgent prior to his disappearance, with Big sending a limousine escort to pick him up. Nick and Judy believe Otterton was attacked before he could arrive, but Mr. Big reveals that it was Otterton who attacked the chauffeur, Mr. Manchas, who explained to Mr. Big that Otterton suddenly went savage and attacked him, though he escaped with a scarred eye. Otterton himself went missing afterwards. Mr. Big advises Judy and Nick to visit Manchas in the Rainforest District if they want more answers.
Mr. Big returns later on, when Judy and Nick ask him to help interrogate a weasel, explaining his will to help due to his fondness for Judy, and the fact that she is personally dubbed the godmother of Fru Fru's expected daughter, whom the former plans to name after the bunny cop. Big's threat to freeze Weaselton to death successfully gives Judy and Nick the answers they were looking for.
Mr. Big is last seen during the end credits, where he and Fru Fru dance together on Koslov's palms at Gazelle's concert together.
Mr. Big is inspired by Vito Corleone (The Godfather) and Tony Montana (Scarface), though his appearance and manners mostly parody Corleone's.
Mr. Big appears to be Catholic and signs are shown throughout the film.
His religion for Catholic is a reference to the Corleone Family from The Godfather, as the family is Catholic as well.
Koslov, his most trusted bodyguard, is shown to be crossing his chest as Catholics do.
Usually, the name "Mr. Big" is used to describe a man who is very important and powerful. This is often used humorously about a criminal leader. However, in the movie, it is unknown whether or not if this is the character's real name or an alias.
In real life, shrews can actually be quite vicious, so it's not entirely ironic for "Mr. Big" to be a shrew.