Jennie

Jennie is a princess of the Emotions Kingdom. Romis cousin and heartsister a kind and innocent girl she actually turns out to be the one who released all the Teeniepings since the beginning. After revealing her true colors she becomes the main antagonist of Alssongdalssong Catch Tinipinghttps://anilist.co/anime/166046/ but then comes back to her senses and is given a second chance by everyone allowing her to become nice again. Source: Catch Teenieping Wiki