Evil Puffy AmiYumi and Kaz are the evil versions of Ami, Yumi, and Kaz. They appear in the episode "Evil AmiYumi".
Evil Ami has wild, darker pink hair. Her dress is much darker with brownish colors, the flower hair clip she wears is pale and pointy and her boots, bracelet and watch are black (with her watch having a red frame. Her eyes are a tad darker than Julie's and her eyelashers are downward. She has facial hair.
Evil Yumi's hair is a slightly darker and wild like Yumi's and her eyes are gray. All of her clothes are black except for her skirt and spiked collar. She also has facial hair.
Evil Kaz's hair is black and has a little more hair than Kaz. His glasses are red, his clothes are gray and he has white shoes. He has a moustache and a goatee.
Their skin is paler and they have sharp teeth.
Evil Ami, Evil Yumi, and Evil Kaz come from the evil alternate universe, so they like causing trouble.
Evil Ami and Evil Kaz flipped signs to cause crashes, barged into a school to scratch the chalkboards and take candy from babies in their world.
Evil Yumi put her drool in a fan's autograph book, switched the toothpaste with shampoo and subjected Kaz to a game called Highway Paddleball.
Evil Ami, Evil Yumi, and Evil Kaz want to ruin music for everyone. Evil Ami and Evil Yumi play their music badly and Evil Ami says that she and Evil Yumi play what they feel like playing.
- In the DS game "Genie of the Amp", Evil Ami and Evil Yumi appear as final bosses, but instead of appearing like in the cartoon, they appear as faceless versions of Ami and Yumi in their perspective colors (pink and blue). Before they go to fight them, Ami tells Yumi she can't imagine what an evil version of herself would be like. Yumi says that she probably hates the color pink, animals, pretty clothes and rock and roll. Ami says that is evil.