an experimental video game for the then-upcoming PlayStation console. At the time, Matsuura was aware of Greenblat's work from his past children's books and CD-ROM projects, and was already using placeholder characters from Greenblat's 1993 CD-ROM game Dazzeloids for the project. Greenblat noted that the team already knew they wanted to a rap music game, and they were looking for someone to handle its artistic side. Matsuura invited Greenblat to work on the project, a call and response game where different musical samples could be plugged in and played to a rhythm like a DJ box, and its characters would be animated to the rhythm. Greenblat was commissioned by Sony to use some of his existing characters and to create a new protagonist. He described the process of character design to be collaborative by nature: he worked with both Matsuura and Gabin Ito, the project's writer, and would create sketches freely based on their suggestions or ideas for a specific character's personality. According to Greenblat, it takes a short time for him to produce character sketches by himself, but a lot more time for an entire team to decide by consensus. He recalled that character designs were sometimes accepted relatively quickly, while others may involve many attempts and revisions before it is finalized. For example, he only needed a fortnight to finalize PaRappa's design, whereas the lead character of the 1999 spin-off title Um Jammer Lammy took approximately half a year by comparison. In terms of characterization, the team wanted to pursue the concept of a player character who would consult with several mentors or instructors who would teach him how to do a rap; the teacher would say one thing, and the player character would repeat it. Greenblat was asked by Matsuura to design several variations of characters that can rap for the game's lead character, with Matsuura initially proposing an anthropomorphic shrimp as the lead character. Greenblat recalled that the team wanted a character who was "trustworthy, loyal, hardworking, romantic and a little insecure". He believed that a dog embody all of these requested traits, and decided to make several sketches of canine-themed rapper characters, and worked with the team to pick out the best design among the character's iterations. Greenblat noted that prior to the release of PaRappa the Rapper, Sony did not yet have a strong mascot that would serve as the "face" of the company