Big the Cat is a Mobian cat and once a citizen of the Mysterious Cat Country. During Dr. Eggman's attempt at using Chaos to destroy Station Square, Big found himself caught in the middle when his friend Froggy became part of Eggman's schemes. Big assisted Sonic the Hedgehog and the Knothole Freedom Fighters in stopping Perfect Chaos. He later aided them in negotiating peace between the Felidae and Wolf Pack Nation, but was exiled for his trouble. Fortunately, there was good fishing up North, so he was pleased nonetheless.
Rescuing A Friend
Big the Cat was an ordinary cat who lived in the deep jungles of the Mysterious Cat Country with his buddy and pet frog, Froggy. A solitary Felidae, he lived apart from his people due to their barbaric traditions, which didn't sit well with him. However, while Big was asleep in his house one night, pieces of rock fell from the sky, causing Froggy to panic and hop towards a mysterious puddle of water. And as Big awoke, Froggy's thirst kicked in and he drank the puddle, not knowing that it was really part of Chaos, the God of Destruction. Chaos' powers then kicked in and Froggy grew a tail. But before Big could question what just happened, one of Dr. Eggman's newest robots, E-102 Gamma, showed up at Big's house. Big thought the stranger was a friend, but was corrected when Gamma grabbed Froggy. Big tried to save his lifelong buddy, but Gamma easily defeated him and escaped. However, Big wasn't going to take this sitting down, and so went off to save his friend. (StH: #80, CSE)
Big found his way to the Mystic Ruins and started searching around a lake on his rowboat. However, it then turned out that the Egg Carrier had been hidden in the lake, and so as it rose up, it brought Big with it. Big then started searching the ship for Froggy, and eventually found him before he jumped inside of Chaos 6. Luckily, Big was able to get Froggy out of the monster and quickly escaped the ship with Sonic's plane, the Tornado. (SSS: #13)
Eventually, Big landed the plane but was knocked unconscious for his troubles. When Big awoke, Sonic, Tails, and Knuckles had arrived and Big introduced himself. But the four then noticed the Tornado was gone and realised that Chaos must have taken it. Big and his new friends headed to Station Square, only to find it flooded and being destroyed by Perfect Chaos. Big then helped the Freedom Fighters battle the beast. (StH: #83, #84)
Big and everyone else who helped fight against Perfect Chaos were rewarded by the President of Station Square, but the ceremony was cut short when Silver Sonic II attacked. Big then helped the Freedom Fighters in battling this foe as well. After the new mechanical Sonic was defeated, Sally Acorn asked Big if he wanted to come to Knothole with them, but he declined and he and Froggy went back to the Cat Country. (StH: #85)
Helping the Freedom Fighters
Big the Cat was present during the mass Mobian rally to combat the Xorda's Quantum Dial during their attack on Mobius. After Sonic's return from outer space, Big was present at Mina Mongoose's concert in Knothole Village. Some time later, Big helped Sonic and others put on a play for some children, him playing the part of Dr. Eggman. Big later attended Bunnie and Antoine D'Coolette's wedding. (StH: #125, #134, #148, #174)
After Sonic and Sally came to visit the Wolf Pack to become honorary members, Big, living on the outskirts of the Mysterious Cat Country, invited Sonic to meet with the Felidae in search of the "Ancient Onyx," which he explained to Queen Hathor with poor timing. When they arrived at the Cat Country, they were met with spearheads and Sonic was not even allowed to explain his actions properly, so Big-despite being looked upon as a lowly fisherman and a traitor for his associations with the Freedom Fighters-was made stately recounter of the truth, even given the appropriate attire. Sonic managed to convince the Queen to allow him to serve as Big's interpreter, as he knew more about the events leading to their visit than Big did. He went on to explain that Big had entered the capital of the Wolf Pack Nation in search of the Ancient Onyx after learning of its disappearance from Felidae territory. Though initially provoking hostility from the Wolves, Big was fortunate enough to find Sonic and Sally in their midst. Big had wondered if the Wolves had taken the onyx themselves, and apologized for intruding. It was then decided that he would guide Sonic into Felidae territory to speak with the Queen, whilst Sally set out on her own investigation. His account finished, Sonic negotiated with Queen Hathor to retrieve the Ancient Onyx if the Felidae let him go. Hathor agreed and asked that he dispose of Big as well, but Sonic instead offered to take Big with him as a form of exile. Big, initially saddened by the thought of leaving his old home, grew more positive after Sonic informed him of good fishing up north. Before the two could leave, however, Chief Lupe of the Wolf Pack arrived with a group of her warriors. (StH: #213)
Queen Hathor was quick to accuse a somewhat confused Big of being a Wolf Pack agent, though he helped Sonic to try and defuse the imminent conflict by standing between Lupe and Hathor, preventing them from coming to blows. After considering recent events, Sonic realized what was going on, and convinced Hathor to lead the Wolves, Big, himself, and her own warriors to the Mystic Ruins. Once there the group engaged a chapter of the Dark Egg Legion led by Drago Wolf and Razorklaw, who had taken Sally captive. Big entered their control room and to his delight found both Sally and the Ancient Onyx, though he then came under attack from the two Grandmasters. Fortunately, his own impressive strength was enough to defeat Drago, and after stopping an attempt by Razorklaw to strike at him he was saved by Sonic. Still giddy over what help he had been to his friends, he accompanied the pair outside with the Ancient Onyx. After Sally arranged a peace agreement between the Wolves and Felidae, Big joined Sonic and Sally in being inducted into the Wolf Pack Nation. He is later seen in New Mobotropolis where he presumably moved to afterwards. (StH: #214, #224)
Living in New Mobotropolis
Big later assisted the Freedom Fighters during Dr. Eggman's attack on New Mobotropolis with his Death Egg Mark 2. When he unleashed Titan Metal Sonic on the city, Big was one of the few citizens who did not run away from the gargantuan robot, instead bravely protecting others like Cream the Rabbit. Big then came to Bunnie's rescue after she got hit by Ixis Naugus' crystallizing magic attack that was aimed at Titan Metal Sonic. Vanilla the Rabbit told Big to bring her to Dr. Quack, and, after the doctor took a look at Bunnie, Big took her to the hospital at his request. (StH: #231)
With the Knothole Freedom Fighters reformed into Team Freedom and Team Fighters Big joined Rotor's team as an applicant during a recruitment drive to help defend New Mobotropolis from internal threats. Together with Cream, Cheese, Heavy, and Bomb, he helped Rotor in their first mission by holding up a building that was about to collapse due to an attack by Tails Doll. It would not be the last trouble the robot would cause, as it later deactivated New Mobotropolis' force field generator, leaving the city vulnerable to invasion by forces deployed from the Death Egg. Big valiantly joined the effort alongside his teammates, carrying Naugus to safety after the king collapsed from pain. He would then engage Metal Amy, and was able to defeat the robot after receiving unseen aid from Silver the Hedgehog of the Secret Freedom Fighters. Shortly thereafter, Tails Doll's actions in destroying the stage of the New Mobotropolis Coliseum spurred Big and his teammates to action, forcing them to save Mina Mongoose and her band, the Forget Me Knots. Big also accompanied Rotor to Antoine D'Coolette's hospital room after the Coyote was taken hostage by Metal Sonic v3.7, but arrived to find Antoine left behind and the robot gone. (StH: #236, #240, #241, SU: #50)
Big and his teammates later attended the ribbon cutting celebrating the restoration of Castle Acorn, only for the structure to start falling apart. Discovering a connection between the recent "accidents" and Tails Doll, Big joined his teammates and NICOLE in setting a trap for the mechanical being at the city power station. However, Tails Doll then surprised them by absorbing a number of nanites to create a monstrous new form for itself, bent on destroying them.(StH: #247)
Despite many people's thoughts, Big is quite intelligent, just laid back, though he can become tongue-tied while under pressure. He cares very much for his friend, Froggy, and will do whatever it takes to save him. Big will also lend out a helping hand where needed, and is quite happy when he can be of help to his friends. Apparently something of an eccentric among his people, Big lived on the fringes of the Mysterious Cat Country prior to his banishment and actually speaks with outsiders, something that his people look down upon.
Due to his immense size, Big is a significantly strong Mobian, as demonstrated by his punching Drago Wolf through a solid rock wall. He is thought to be one of the strongest beings on Mobius, rivaling the likes of Mighty the Armadillo or Bark the Polar Bear. His girth acts as rather effective defense, though his unblinking, off-putting gaze is often enough to deter most opponents. This is pretty much his only ability, except for his skill at fishing, at which he is a master. (CSE)
- Although it is assumed that Big was one of the many captured by Eggman's Egg Fleet and was sent to New Mobotropolis, when answering a question asking if Team Rose from Sonic Heroes would be introduced, Ian Flynn said "We'd need to bring Big in from the Mysterious Cat Country, and we'd need to introduce the Rabbit Family all before we could get to Team Rose." 
- In the time since, Big has been exiled from the Mysterious Cat Country and presumably traveled to New Mobotopolis, and Cream and Vanilla have also been introduced.
- Big's appearance during the Sonic Adventure adaptation mirrors the fact that Big first appeared in Sonic Adventure itself, though there are obvious differences.
Big is a very large and burly cat. The majority of his body fur consists of two shades of purple: light and dark. A striped pattern runs up his arms and tail. His feet are covered in dark purple fur up to his ankles as well as the outer tips of his ears, while his upper legs, back, and sides are covered in light purple fur. White fur covers his chest, torso, and inner ears. His eyes have yellow scleras with black irises. His preferred attire consists of tan gloves, sandals, and a matching belt with a gold buckle. He carries a fishing rod with him at all times. As Stately Recounter of the Truth, Big was outfitted with green pants, a brown, gold, red, and cream poncho and a metal headdress with trim, flowers, and blue beads.