Throughout development of "Red" and "Green", all Pokémon were designed by Ken Sugimori, a long-time friend of Tajiri, and a team of fewer than ten people, including Atsuko Nishida who is credited as the designer of Pikachu. By 2013 a team of 20 artists worked together to create new species designs. A committee of five people determine which designs are incorporated into the games, with Sugimori and Hironobu Yoshida finalizing the look of each creature. Furthermore, Sugimori is responsible for the boxart legendary Pokémon and all of the official artwork for the games. According to Yoshida, the number of rejected Pokémon designs is five to ten times more than the number that are finalized in each game. In rare cases, rejected designs are brought back and released in a later generation. Shigeru Ohmori, director of "Sun" and "Moon", admitted that creating new Pokémon has become a difficult task with the sheer number of creatures designed over the franchise's 20-year history. Each iteration of the series has brought about praise and criticism over the numerous creatures.