Mr. Big is an Arctic shrew who has the reputation of being the most feared crime boss in Tundratown despite his small size. However, he is quite cordial to his allies, and helps out Judy and Nick with the Weaselton interrogation. It also appears that he wishes to be friendly to non-underworld people like Otterton and Nick (considering the former "like family" and inviting the latter for a dinner) and contacts them depending on their specialty.
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 who wanted 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.
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 various signs are shown throughout the film.
His religion being 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.