Paper Mario Beta Archiveさんのイラストまとめ

There is an unused orange snake-like enemy likely known as “Mander” seen in a screenshot found in the files of the game. There would’ve been different variants including bosses such as “Kingmander” and “Honemander” (Bone Mander).
(Artwork by @Fawfulthgreat64)

This design choice could've been originally made because the Wiggler artwork from Super Mario World has the pink flower and the Paper Mario series was heavily influenced by the art styles of SMW and Yoshi's Island up until that point.

The Wiggler in the E3 2010 build had a pink flower, similar to the unused Wiggler sprite in Super Paper Mario.