In the original, Suika was a cute and sweet girl.

Here, her cuteness is a front for her more crazy, psychotic, sadistic, murderous personality because no one suspects the cute girl. lol 

and the melon hides her scary side. 

(Note: she even scares Senku and is good friends with Kohaku).

Based off of DBZ Abridged's Lord Popo if you're looking for an inspiration.