Nero

Hero (real name: Nero) is the hidden main antagonist in Disney's 2019 animated film, The White Sheep and the Black Sheep 2. He is the Count McAlpin's heart that the MacAlpin accidentally brought to life.

Biography
After Count McAlpin accidentally brought his heart, named Dr. Nero to life, the heart wanted to seduce Kira with science so he could rip out her heart and make it his wife. He is defeated by Jedi, and Count McAlpin puts him back in his chest, with Nero vowing vengeance.

When McAlpin dies, Nero actually escapes from his body and using McAlpin's internal parts to build a larger body for himself. This time, he kills the King and Queen by toasting them with a poisoned kool-aid. He explains that he was thinking too small last time, and now wants to separate Kira and Jedi's love and later marry Kira entirely, not just her heart. She challenges him to hand-to-hand combat that if he won, she would marry him. She quickly hit the exposed tendons of his newly built "body" and defeated him, telling him to get out of her sight.