Viristal has the highest base Special Attack stat of all Rock-type Pokémon and all non-legendary Electric-type Pokémon..
One of the proposed names for it during development was Bacbulb.
Before the official release of Clover, the shiny form appeared with lime green legs rather than grey.
Additionally, Viristal had a larger lightbulb head before the official release.
Viristal is the only Pokémon to have its shiny appearance change within its evolutionary line.
Viristal is a strange mix between a bacteriophage, a crystal and a lightbulb. Its blue coloration, power of electricity, and "0w0" face could be a nod to Kamen Rider Blade, where the titular character is a blue bug-themed hero with electricity based attacks. Japanese fans often draw chibi versions of the character with a simple "0w0" face.