Raigender is a xenogender that is connected to the Pokémon Raichu or a gender that is defined as "A gender that feels fuzzy with a larger electric charge".
Shinyraigender is a shinygender variant of raigender. other terms for this gender include shinyraigender(chu), raishinychugender, raichushinygender & shinyraichugender.
History
The term appears to have been coined sometime before January 27th, 2019 by tumblr user "chibiusapositivity".[1]
Flags
The original Raigender flag was created by tumblr user "chibiusapositivity" when the term was coined.
The Shinyraigender flag was created by tumblr user "imoga-pride" on January 27th, 2019.[2]