Eva (Ima in Italian and other languages) is Princess Ava's evil twin sister and the main antagonist of the series. She is one of the two kittens of the fictional Felis aulicus breed ("Cat of the Royal Court" in Latin), the rarest cat species known to people in the Big City.
Jealous of Ava's position of power, she hatches a plan to steal the Friendship Heart while her sister is busy with the Friendship Ceremony. She ends up breaking the Friendship Heart in two and accidentally sending Ava to the Big City. She escapes capture with one half of the jewel, leaving the other half in the heroes' paws.
Determined to become the next monarch of the Pocket Kingdom, she does everything she can to recover that half and keep Kate, Magic, and the Royal Guards from bringing Ava back. As fate would have it, however, this dark obsession leads to her end as the Petbuster's prisoner.
Her defining characteristic is jealousy, since she was very jealous of Ava and that’s what drove her to do such bad things. However, she was only jealous for Ava’s power. That’s not to say Eva is without authority herself- She shows it very well when she deals with her lackeys.
Eva is intelligent, clever, devious and always devises cunning plans. However, they fail all the time (due to Zull and Gort’s incompetence). She knows a lot about laws in Pocketville, and she knows how the Pocketpedia works. She managed to lure Kate and the Royal Guards by bringing Leo to the Ever Grey Swamp. She even won over the Pet Buster by striking a deal to send him pets in exchange for keeping Ava prisoner. She is able to detect weaknesses in people, like with the snow leopard protecting the Never Alone Flower.
She is also incredibly brave, as she decided to stay in the Ever Grey Swamp, a place other pets fear and would never go to (even Zull and Gort were hesitant). It adds to her cleverness because she knew nobody would come to stop her. She also dared to meet Durillia, someone who lots of people feared, and she showed no hesitation or fear.
She is also a creature full of hatred. She hates everyone, including her lackeys, and she hates her own sister the most. In Operation Princess, she tells Ava that she’s hated her for her entire life, and she had even tried to kill Ava in the past by breaking a large tree branch, but only ended up injuring her leg, which Ava believed was simply an accident. However, there is no way that Eva would hate her sister ever since she was born, since it wouldn’t make sense, so it was speculated that she was lying.