The term 'EVILDOER' is an 8-letter crossword solution for the phrase 'THE JOKER OR THE PENGUIN'. Both characters are villains from the Batman universe. The Joker is a psychopathic criminal mastermind who is known for his dark sense of humor and chaotic nature, while The Penguin is a devious criminal mastermind who uses his wealth and influence to commit crimes. Both characters are considered to be evil doers in the Batman universe.