Butterbae

Butterbae is a Butterfree that was caught as a Caterpie by Athena in Moemon. During a battle with Young Couple Lea and Jed, she got into a friendly fire incident with her partner Accio, resulting in the Vaporeon fainting.

Name
Originally she had no nickname, but after evolving into Butterfree she was given the nickname Butterbae. An effort was made to give her the nickname Butterbae, but she was given the nickname BUTT as a joke before she was fully renamed to BUTTERBAE.

"Bae" is a slang term for a significant other. Given the feminine redesigns of the sprites, terms such as "waifu" and "bae" have become abundant.