- “There's no escape this time, Basil!”
- ―Ratigan during the final battle
He is the story's version of Professor James Moriarty from Arthur Conan Doyle's Sherlock Holmes stories, and serves as the adversary to the Sherlock Holmes counterpart Basil of Baker Street. He has cited the "Big Ben Caper" and the "Tower Bridge Job" as two of his most notorious criminal operations.
Ratigan is a towering rat with gray fur dressed in a dark gray suit complete with a long black cape with a red underside. His face is shaven and has yellow eyes with lavender circles around them, above them are thick eyebrows. Although he lavishes himself as a mouse, he has rat-like characteristics, such as sharp fangs and fingers, a large nose, and a long, pink tail. On his head, he wears a black top hat with a gray band, which covers his black combed hair. His suit includes a high white collar and a gray vest with buttons on it with a pink-and-purple striped cravat. On his hands are white gloves and cuffs with golden cufflinks. He is always seen carrying a gold cane.
However, when Ratigan becomes completely enraged, he becomes incredibly feral, running on all fours in a hunched position. His hair becomes messy and his clothes become torn exposing his intimidating physique as Ratigan becomes vicious as he obtains a more rat-like appearance. His nails and teeth also grow longer and gnarly.
Ratigan has a variety of henchmen that follow him, including his overweight pet cat Felicia, Bill the Lizard, a small mouse named Bartholomew, and his right-hand man, a peg-legged bat named Fidget. Personality-wise, Ratigan is very charismatic, calm, and calculating, but can easily be sent into a violent rage at the mention of Basil or by the incompetence of his minions. He has a very dark, malicious sense of humor and an inflated ego. Unlike most Disney villains, Ratigan is an ebullient, lip-smacking jester who has a tendency towards big movements and long rants or speeches.
Even though he is one, Ratigan detests, above all else, being referred to as a rat, preferring the description of a "big mouse," and fed Bartholomew to Felicia when Bartholomew calls him the "world's greatest rat" while intoxicated. He can easily be identified as a rat since he has four fingers and a thumb on each hand, while all the other mice have three fingers. Also, the mice in the movie have fur-covered tails that much thinner than Ratigan, who has a pink, fleshy segmented tail. Despite his hatred of being labeled as such, he possessed enough self-control to barely react when Basil referred to him as a rat, which is evidenced with two instances in the film: The first, right after he trapped Basil and Basil called him a sewer rat, Ratigan retained his cool demeanor, only closing his watch, and the second time, when Basil revealed his survival after the literal breaking down of the fake Queen of Moustoria by finishing her sentence of Ratigan being a rat, only growling in irritation. In the Basil of Baker Street book series, Ratigan's first name is revealed to be Padriac, and he is in fact, portrayed as a mouse (in contrast to his depiction in the movie).
Ratigan makes plans to take over Mousedom by replacing the Queen with a robotic fake built by a toymaker named Hiram Flaversham, whom he has Fidget kidnap. He will then have the real Queen fed to Felicia, ensuring his reign as permanent King of Mousedom. Although Flaversham is reluctant to help, Ratigan threatens to harm Olivia, and this gets the prisoner back on course. He then reveals his plan to his followers, but not before having one gobbled up for "insulting" him. Just as his plan is nearing completion, Basil and his new companion, Dr. Dawson, bring Olivia along and they are able to intervene in the final stages. Learning of their involvement from Fidget, Ratigan sets up another trap that nearly leads to Basil and Dawson being pummeled by a barrage of life-size weapons. However, Basil turns the tables and escapes with Dawson and Olivia. They head back to the palace, and reveal the plan in front of all the citizens of Mousedom. Ratigan's plan is foiled. Unfortunately, Ratigan, with help from Fidget, kidnaps Olivia again and threatens to kill her if they attempt to stop his escape. Basil, Dawson, and Flaversham pursue Ratigan above the Thames River on a quickly-made hot air balloon. Fidget, who is pedaling Ratigan blimp to speed it up, cannot take the extra weight and tells Ratigan they have to lighten the load, meaning to throw Olivia off the balloon. Ratigan, out of sheer bad temper, throws Fidget (who can't fly) off the blimp and into the Thames River instead. With Fidget destroyed for good, Ratigan tries to pedal the blimp himself. Basil jumps onto the blimp, distracting Ratigan and causing his dirigible to crash into the upper half of Big Ben.
Inside the clock tower, Ratigan recovers, seizes Olivia in one hand, and attempts to ambush Basil. Basil, however, notices him, and the two fight atop the gears of the clock tower. With Olivia's help, Basil traps Ratigan by throwing his cape in the gears. The two mice then escape and Basil is able to take Olivia to safety. This finally sends Ratigan over the edge. Breaking free from the gears, he pursues Basil, tearing his clothes in the process and transforming from a very formal, composed rat to a highly savage one. Ratigan leaps into Basil and they both tumble onto the clock's hour hand; Ratigan stops Basil from reaching the others. Finally, he extends his long, strong fingernails and begins scratching, punching, and strangling Basil continuously. The attack leaves Basil with torn clothes and several wounds. Attempting to finish him off, Ratigan knocks him off the clock hand and yells in triumph, thinking he has won and killed Basil. However, Basil called him, saying to him that the game was not yet over. Ratigan glances down and sees Basil holding on to the broken blimp. Basil rings Ratigan's bell which he used to summon Felicia, realizing that he stole the bell during the fight and already lost the battle. Suddenly the clock bell tolls, causing Ratigan to lose his balance, and plunge off the hand, taking Basil with him. Basil manages to save himself while Ratigan falls off Big Ben to his death.
His death later made the headlines (a newspaper headline was seen that stated that "Time Runs Out for Ratigan.")
In an episode of Quack Pack, Ratigan can be seen on the box art of criminal trading cards.
Ratigan most notable cameo on House of Mouse was in the episode "Donald's Lamp Trade", in which he tries to lure Dr. Dawson with cheese on a mousetrap, but Basil stops Dawson and tells him it's a trap, at which point the nearby Ratigan groans "Curses!" He is also seen with several other mice in "House of Scrooge". In many instances, Ratigan can also be spotted seated alongside other Disney villains, or at times Fidget in recurring crowd shots.
Ratigan was once a walkaround character at the Disney parks during the film's initial release. But he has been retired, rumoredly because he frightened children. His last appearance was at a special event at the Magic Kingdom in 2004.
Proffesor Ratigan is one of the villains brought back to life to be imprisoned in the Isle of the Lost. It is mentioned once that he and his crew went to Ursula's Fish and Chips Store and every time they go there, Ursula chases him out.
- Ratigan is shown to have an animation flaw. If you look closely during the course of the film, Ratigan has five fingers on his hands. However, during the battle sequence from when he goes feral to when he falls to death, he is shown to have four fingers on each hand minus when he flared his claws.
- Ratigan seems to grow in size during his breakdown in Big Ben, and his claws are shown extending out of his hand. This transformation could be compared to that of a stereotypical Werewolf.
- According to a deleted lyric in "World's Greatest Criminal Mind"; the Tower Bridge Job involved hurling several innocent mice within the River Thames and then shooting whoever attempts to come up to the surface.
- Vincent Price, the voice of Ratigan, said that doing Ratigan was his favorite role because he had two songs written for him.
- Ratigan is the first Disney villain to just fall to his death since the disguised Queen from Snow White and the Seven Dwarfs, Disney's first feature length film since 1937. Maleficent's death included falling, but she already suffered a fatal wound from the Sword of Truth piercing her heart before falling to her death.
- In the novel that the film was based off of, Ratigan is actually a mouse, despite his name. This was changed for the film.
- Ratigan is the only Disney Villain to record a song in advance for their foe.
- Ratigan is the first Disney Villain to sing his own villain song since Kaa in 1967.
- Even though it is believed Ratigan died in the climax, the same newspaper that says Basil and Dawson were thanked by the Queen also says "Time runs out for Ratigan". This implies he, like Basil, survived but is presumably dying of his injuries from his fall but it can also imply Ratigan is on the brink of facing prison for his crimes. And some Italian comics with Basil say that everybody thought that he was dead when he fell, but that he in fact survives; and so he appears in a few stories. That could also explain how he appears alive in House of Mouse, even if there is not obligatory any need of an explanation for this latest fact (as Ratigan would not be the only villain supposed to be dead but still appears in the show, others including Claude Frollo, Shan Yu, Gaston etc).
- Ratigan is the third Disney villain to be a rodent, following The Rat from Lady and the Tramp, and The Mouse from Goliath II.
- Despite coming out of Disney's Dark Age, Ratigan is commonly regarded to be one of the more iconic and popular villans, and to possible extent Madame Medusa and Prince John, to come out of that time period. Most argue that Vincent Price's performance is the main reason why.