A big-name producer worried about the future of the music industry. Def Big is currently seeking a pop sweetheart newcomer sensation with urban integrity but with a dark side too. — Directory, Sonic Unleashed
Def Big (デフ・ビッグ,Defu Biggu?) is a character that appears in the PlayStation 3/Xbox 360 version of Sonic Unleashed. He is a human resident of Empire City and a legendary record producer in the music industry. The hottest name in Empire City, he is also a gifted talent scout who seeks out people to become the world's next pop sensation.
At some point, Def Big became an extraordinarily successful record producer and a producing legend in Empire City. Despite his success, however, Def Big worried about the future of the music industry, regarding finding a new popstar sensation that could take the world by storm.
During Sonic Unleashed, Def Big noticed the uprising in Dark Gaia's Minions in the city following Dark Gaia's premature release. Later on, he met Sonic the Hedgehog and Chip when they first arrived in Empire City, where he asked Sonic if he was satisfied with his everyday grund, before warning him that the streets had become very dangerous at night and to watch himself. Later, during the night, Def Big met Sonic and Chip again, after they had driven Dark Gaia's Minions away. Having noticed that Dark Gaia's Minions had left, Def Big talked with Sonic about their absence and thought that he had positive-thunk them out of existence.
Eventually, Def Big decided to hold an singing audition in the current week to find a new popstar sensation, especially looking for a sweetheart newcomer with urban integrity and a dark side. For this audition, Def Big told others that they had to send in a demo tape with them singing, and he would then personally choose the winner. During this week, Def Big was brought to Shadi by Sonic. Having been told by Sonic that Shadi sought help to become a professional singer, Def Big introduced himself when Shadi asked who he was, and told him about his singing audition. All Shadi had to do was to send him his demo tape and then he would judge if he had what it took to be a singer. At the end of the week, Def Big was given Shadi's demo tape by Sonic, minutes before the deadline.
With the audition over, Def Big went through the demo tapes and eventually narrowed his choices down to two: Shadi, who showed a lot of talent, and Li'l Kate, who got "pipes", but was unable to choose between either of them. Later, while on one of his nightly scrolls in Skyscraper Scamper, Def Big was brought by Sonic to Li'l Kate, who wanted to hear if she had made the cut. Initially, Def Big was confused of what was going on, but when Li'l Kate introduced herself and told why she had Sonic bring him here, he recognized her from her demo tape. Def Big then admitted she had talent, but also remarked that his other choice, Shadi, had talent too, and that he was still deciding between them. As Li'l Kate was shocked to be one of the two candidates, Def Big noted that not was final yet before telling that he would see her around and left.
On the night where Def Big would announce the winners, he was brought to Shadi and Li'l Kate by Sonic, as both Shadi and Li'l Kate were anxious to know who won. There, Def Big admitted to Sonic that he was wondering too of who got to be the next singing sensation, as he was unable to choose between Shadi and Li'l Kate, and that he was dying to make that decision now. As Sonic asked for advice on this situation, Def Big remarked that he did not have any advice for people without grove. Deciding to test if Sonic got grove, Def Big challenged him to freestyle rapping with him by coming up with rhymes to his sentences. After exchanging some successful rhymes, Def Big remarked that Sonic's rhymes synched up right to his beats. Suddenly struck by inspiration, Def Big figured out a solution to his choice between Shadi and Li'l Kate; Rather than choosing one of them, he decided to have Shadi and Li'l Kate debut as a two-person act, believing that their voices would make the perfect combination, and told Sonic that he could feel they would be big singing stars.
Having made his choice, Def Big announced his decision to Shadi and Li'l Kate, who gladly accepted the result. A while later, Def Big met up with Sonic again, and told him that Shadi and Li'l Kate's voices blend for some fresh chemistry and that he expected Shadi and Li'l Kate would make it big time.