Character: wapeach
Wapeach was originally designed by Fumihide Aoki, the character designer of Waluigi, as a potential playable character in Mario Tennis and/or its sequel, Mario Power Tennis, but the concept was rejected by Nintendo. In late 2023, the Instagram account "yuzumpo" shared a character illustration labeled with the text 「プリーチ ワルピーチ」 (Preach: Walupeach), then later deleted the post.
According to fan questions Aoki answered before he took his Wapeach posts down and privated his Instagram account, it's possible that she would have been a descendant of a fallen royal family, and that she would have been notably younger compared to Wario and Waluigi, giving them the dynamic of a bossy rich girl ordering her lackeys around. Aoki also stated that he considered giving her a dragon-like Yoshi companion with horns and wings. He admitted to not being aware of the creation of Boshi - known in Japanese as ワッシー Wasshī - for Super Mario RPG: Legend of the Seven Stars, so it's possible that this was a coincidence on his part.