Creating an evil character for a movie is pretty easy. All you need is a facial scar, some innocent people for the bad guy to kill, and you're more than halfway there. But it takes verve to create an insane character, one who audiences remember not for the content of his character, but the insanity of his membrane. Here are seven of the most insane characters in the history of film.

Alonzo The Armless, "Th Unknown." Lon Chaney specialized in playing insane characters that you nonetheless feel sorry for, and "The Unknown" is perhaps the best example of this. As Alonzo, Chaney will do anything and everything to get the girl, and the madness that gleams in his eyes when he sees that he's lost her, is truly terrifying. Also, how crazy do you have to be to drink wine with your feet? Gross.

Dr. Gogol, "Mad Love." Peter Lorre is another actor who is famous for portraying a character with a diseased mind. And the "Mad" in the title of this 1935 film doesn't refer to anger. Gogol is a brilliant surgeon who is in love with an actress at a "hall of horrors" stage show. When she goes to live with her husband, Gogol is upset. But a train crash gives him the chance to operate on her husband's hands, and he goes to increasingly insane lengths to make Yvonne his. Among his crazy actions are masquerading as a resurrected recently-executed murderer by placing a grotesque brace over his neck and face in order to drive Yvonne's husband mad. Ah, that's quality insanity.

Captain Will Stone, "The Ghost Ship." One of the scariest things about going insane in knowing that you're gradually losing your mind and there's nothing you can do to stop it. That's what's happening to Captain Stone in this horror classic, and that awareness doesn't keep him from murdering members of his crew he considers to be defiant. In his crazy world, his authority as captain of the ship gives him rights over the lives of his crew, which extends to being able to murder them at will.

Bruno Anthony, "Strangers on a Train." Just because you're completely bonkers doesn't mean you can't hatch a brilliant murder scheme. In this case, the scheme is that Bruno and his tennis-playing idol Guy Haines will swap murders. Bruno will kill Guy's horrible ex-wife, and Haines will kill Bruno's domineering father. The problem is that Guy doesn't want to kill anybody, so Bruno just kills his ex-wife anyway. And guess who the prime suspect in that crime is. See? Brilliant. Completely insane, but brilliant.

Norman Bates, "Psycho." You shouldn't be too surprised to find out that Norman is insane—after all, just look at the title of the movie. Like a lot of insane people, Norman was made that way by his demanding mother. So he killed her, of course, and had her dead body stuffed so he can still talk to her. Oh, and he talks for her too, and dresses up in her clothes. One more thing: Sometimes when he's dressed up as Mother, he stabs people and hides their bodies in the swamp out back. He may seem charming (when he's not dressed as his mom), but Norman Bates is undoubtedly insane.

Alex DeLarge, "A Clockwork Orange." Alex is going through his "wild years," which might make you think he's going around smashing mailboxes, but he's actually committing violent rapes for fun. This "ultraviolence" is how Alex gets his kicks, until an authoritarian government brainwashes him into living the right way. There are no clear rights and wrongs in "A Clockwork Orange," but Alex is undeniably insane—almost as insane as the world he lives in.

The Joker, "The Dark Knight." Few characters encapsulate criminal insanity as well as The Joker. And his portrayal by Heath Ledger in "The Dark Knight" is the most unhinged cinematic take on the character yet. The Joker simply blows up or beats to death anybody that's in the way of his insane schemes, and those schemes aren't even of the conventional criminal kind. He just wants to push Gotham City over the brink of madness. Insanity for insanity's sake is The Joker's motto.