Don Patch's name is a pun on "donpachi", the Japanese sound of machine gun fire, and the name of a Japanese confectionery similar to Pop Rocks, which is why he is named "Poppa Rocks" in the English translation of the manga. In the English translation of the anime, he is called Don Patch. He is an orange, round creature, possibly a parody of Sonic the Hedgehog or Ristar.
He was the original leader (or "don") of the Wiggin' Gang", a group of rebels who oppose Tsar Baldy Bald IV. Don Patch has henchmen named Baby Patch. He quits the Wiggin' Gang claiming that they never gave him space, but really so he could wig out more with Bo-bobo.
In some episodes Don Patch or other characters will mention that he hasn't taken a certain medication of his, which indicates that he might be somewhat mentally ill but this hasn't been truly proven yet (and likely never will be). In the most recent (and possibly final) popularity poll of the series, he was the most popular character, and his Super form came in seventh.
Don Patch is a happy-go-lucky character, more so than anyone else on Bo-bobo's team. While facing extreme danger and the many powerful and troublesome threats in this world, he usually keeps his chin up and either finds or says something that completely destroys the mood of the battle or makes things even more bizarre. Most of his cheerfulness comes from his hajike way of life, where he must always be doing something bizarre or else he'll be completely uncontrollable. Even during the most serious times, Don Patch can never take anything too seriously (nor can any of the other principal characters for that matter, save Beauty and Gasser).
Unfortunately, Don Patch's desire to consistently wig out or be the center of attention makes him narcissistic in nature. Whenever the focus isn't on him, he always tries to find some way to make everyone pay attention. His feelings are particularly seen this way towards his allies, of whom he finds himself more important than throughout the series. He tries to promote himself as main character over Bo-bobo, he tries to become the main heroine over Beauty, he even tries to force himself as greater than similar ally Jelly Jiggler! Usually, these streaks of attention desire are beaten away from Don Patch, either by being beaten up by an enemy, beaten up by Bo-bobo or even talked down upon by Beauty!
Several other aspects of Don Patch's personality occasionally come into play whenever needed. Although he is no longer leader of the Wiggin' Gang, he still obtains great respect from hajike followers, including the Baby Patch, and the human followers, Underboss and Hatenko. Don Patch uses these moments to show his leadership qualities, but usually they lead to him becoming bossy or self-serving. He has also exhibited a matronly side (and not just when he cross-dresses either!), usually in care of his toy doll Ya-ya, but occasionally in Wiggin' gags with Bo-bobo. And there are even moments where Don Patch does try to show a more serious side...yet those usually end up as set ups for a joke.