Acting for Two: Throughout the series, there is a number of actors who have voiced many numbers of characters. They include:
Michele Burks as Katy Kat and Cheap Cheap the Cooking Chicken in PaRappa 1.
Armstead Christian as PJ and Papa PaRappa in both the original PaRappa game and its 2001 sequel.
Saundra Williams as Instructor Mooselini, Chunky Burger Restaurant Manager, and vocalist for the song "Funny Love".
Ryu Watabe as Joe Chin, Chop Chop Master Onion, PaRappa 1's TV Announcer, Ma-san, and Captain Fussenpepper.
MC King Kong Mushi's voice actor, Richard Bush, also does the voices of the Two Punks in both PaRappa games, and Chief Puddle in Um Jammer Lammy.
Dean Bowman, King Kong Mushi's Other Darrin in PaRappa 2, also does the Guru Ant.
Freedom Bremner as Boxy Boy and Hairdresser Octopus in PaRappa 2. This is referenced by Boxy Boy briefly quoting Octopus's "Okay baby, let's go, we gonna do it like this" during two-player mode.
Corpsing: Dred Foxx can't help but laugh a bit during his "melt the cheese" line in the second game's first stage, when Beard Burger Master lets out an excited "OW!" between his lines.
Executive Meddling: Lammy was originally meant to be younger and actually resemble a lamb/sheep. Sony's higher-ups did not approve, so they forced the developers to radically alter her design to make her sexy and older, and remove all sheep-like traits except for the antlers, pointy ears, and round nose. The end result turned out to be a success, as her final design got lots of praise from critics, gamers, and the Furry Fandom.
Franchise Killer: The first game became an instant hit when it was released and invented the Rhythm Game genre. Um Jammer Lammy continues the trend that PaRappa started, but it didn't sell quite as well due to being more or less the same as PaRappa, including being just as difficult. While PaRappa the Rapper 2 isn't a bad game, the game was given lower scores than the two games before it due to not changing the formula, and was also criticized for being too easy. Aside from the games being rereleased on the PSP and PlayStation Network, the franchise was done for when the rhythm game genre moved on. Parappa appeared as a fighter in PlayStation All-Stars Battle Royale and Sony released a remastered version of the first game in 4K graphics for the PlayStation 4, but there seems to be little interest in continuing the series.
Real Song Theme Tune: In the intro to the fourth stage right after the "I gotta believe" part, when the announcer is announcing Cheap Cheap's cooking show, a snippet of "Tijuana Taxi" by Herb Alpert and the Tijuana Brass (played in a slightly slower tempo) can be heard.
Role Reprise: Master Onion is the only character in the anime to retain his voice actor from the games, which also makes him the only character with the same voice in both English and Japanese.
Throw It In!: Most of Beard Burger Master's improv in "Toasty Buns" isn't scripted, most noticeable when he gets PaRappa's actor to crack up while he says "melt the cheese."
Urban Legend of Zelda: Rumors suggested that one could play as Sunny Funny or as Chop Chop Master Onion in the original PaRappa.
Early concept art shows that PaRappa's early design had a baseball cap and a regular shirt with the letter P on it and different shoes. It also shows that PaRappa had a different personality.
Early concept art from a 2001 Japan Report magazine shows that he was originally an onion-headed kid, a clam, a dragon, and a wolf, although the first drawing of him was a shrimp. The onion-headed kid design ended up being used for the background students in Chop Chop Master Onion's stage.
The game's story was different due to it having to be changed due to Greenblat's many designs of the main character.
Originally there were 7 stages but was cut down to 6, evidenced by a Dummied Out file. There was a stage between Prince Fleaswallow's stage and Cheap Cheap the Cooking Chicken's stage listed as stage 4, meaning Cheap Cheap's stage was meant to be stage 5. This stage would have had Sunny's father General Potter as the master of the stage.
The first game's gameplay had various concepts; one of them interestingly involved playing the guitar. This concept was later used in the game's spin-off Um Jammer Lammy.
Concept art for PaRappa's friend group shows that the gang was originally going to have a Token Human friend named Pony Pony.
Creator Killer: Greenblat's stress with working on the anime (in which he was character designer and had no creative input besides), combined with the fact that he felt that he was unable to come up with anything as successful as PaRappa, effectively drove him out of the video game industry (although he with Matsuura attempted a failed comeback with the 2009 flop Major Minor's Majestic March).
Disowned Adaptation: The art designer for the games, Rodney Greenblat, didn't like the anime. It was too kiddie for him and he thought it was mediocre at best. Sony didn't allow him to be involved in the anime outside of drawing character designs, which also annoyed him.
No Export for You: Despite the video games great success there, the anime was never given an English dub and released in the USA. This probably relates to it being only a modest success in its home country. It was, however, shown in the Central Europe region with subtitles. There's a Latin American Spanish dub as well.
Screwed by the Merchandise: The anime was made to sell toys to kids but the series wasn't popular enough, so it finished at only 30 episodes.
Screwed by the Network: The anime wasn't successful with kids. It also had the misfortune of being in a time slot where it was often rescheduled due to baseball games.
was the reason why there wasn't a PaRappa the Rapper 3.