@Mami Outfit can be found here! The cow outfit is included in the full package version (last image on store page).
I'm glad I could find what outfit it was for you!
https://booth.pm/en/items/2285016

For this avatar don't forget to download and import the shader for the glasses!
Know it says on the store page too but throwing it here too
https://booth.pm/ja/items/1035152