Masakazu Katsura), but most notably his editor Kazuhiko Torishima as the series' main antagonist, Dr. Mashirito. A running gag in Dr. Slump that utilizes feces has been reported as an inspiration for the Pile of Poo emoji. When Dragon Ball began, it was loosely based on the classic Chinese novel Journey to the West, with Goku being Sun Wukong and Bulma as Tang Sanzang. It was also inspired by Hong Kong martial arts films, particularly those of Jackie Chan, and was set in a fictional world based on Asia, taking inspiration from several Asian cultures including Japanese, Chinese, Indian, Central Asian, Arabic, and Indonesian cultures. Toriyama continued to use his characteristic comedic style in the beginning, but over the course of serialization this slowly changed, with him turning the series into a "nearly-pure fighting manga" later on. He did not plan out in advance what would happen in the series, instead choosing to draw as he went. This, coupled with him simply forgetting things he had already drawn, caused him to find himself in situations that he had to write himself out of. Toriyama was commissioned to illustrate the characters and monsters for the first Dragon Quest video game (1986) in order to separate it from other role-playing games of the time. He has since worked on every installment in the series. For each game Yuji Horii first sends rough sketches of the characters with their background information to Toriyama, who then re-draws them. Lastly, Horii approves the finished work. Toriyama explained in 1995 that for video games, because the sprites are so small, as long as they have a distinguishing feature so people can tell which character it is, he can make complex designs without concern of having to reproduce it like he usually would in manga. Besides the character and monster designs, Toriyama also does the games' packaging art and, for Dragon Quest VIII, the boats and ships. In 2016, Toriyama revealed that because of the series' established time period and setting, his artistic options are limited, which makes every iteration harder to design for than the last. The series' Slime character, which has become a mascot for the franchise, is considered to be one of the most recognizable figures in gaming. Manga critic Jason Thompson declared Toriyama's art influential, saying that his "extremely personal and recognizable style" was a reason for Dragon Ball'''s popularity. He points out