For all you Batman fans out there, you must have noticed something off about every single villain in the franchise. Arguably, there are certain peculiar behaviors that each one of them exhibits. Then there's also the question of their history; what fuels their passion to commit crimes.

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Batman villains portray a certain form of mental illness that has led them to behave the way that they do and, in one way or another, explains their decision to opt for a life of crime. So, without further ado, here are ten villains and the real-life mental illnesses they epitomize.

10 The Penguin - Inferiority Complex/Narcissism

It comes as no surprise that The Penguin suffers from an Inferiority Complex. He always prefers to be surrounded by beautiful women and tries to exert his power over others. His self-absorbed, narcissistic ways are also elucidated by the fact that he keeps presuming that Gotham needs him. Who's going to break the news to him? Not it.

9 Mad Hatter - Paranoid Schizophrenia

Mad Hatter with blood splattered on him

This was perhaps the most obvious one. Wandering off to unknown lands and hearing 'hats' talking in his head, Mad Hatter is an immaculate portrayal of a paranoid schizophrenic. This profoundly deluded genius is often shown mistaking real people for Wonderland characters. That's kind of sad, minus the evil part.

8 Mr. Freeze - Complex Bereavement Disorder

Mr. Freeze sadly watching over a frozen Nora Fries in DC comics

Mr. Freeze's mental illness stems from a very early age when his parents sent him off to boarding school in the hopes of curing his 'freezing hobbies'. There, he led a life of isolation until he met his wife, Nora. She was the light of his life, the apple of his eye. Unfortunately, she didn't make it very long and her passing took a toll on Mr. Freeze's mental health. Grieving over her cryogenically frozen body, Mr. Freeze shows symptoms of Complex Bereavement Disorder including numbness, depression, and intense denial over a loved one's death.

7 Black Mask - Sadistic Personality Disorder

Black Mask from DC Comics

Shown as Gotham City's criminal boss man, Black Mask is known to elicit sadistic pleasure out of tormenting and abusing others. A true master of physical and psychological forms of torture, he leaves no stone unturned when it comes to obtaining intel that could prove valuable for attaining his means. A sicko in every sense of the term.

6 Firefly - Pyromania

Firefly from DC Comics.

It might as well be forged on his forehead that he likes destroying with fire. Pyromania is a real-life mental illness categorized by a strong urge to light things on fire. Pyromaniacs are known to be highly fascinated by fire and the act of burning something is the only way for them to relieve their built-up tension. Yikes.

5 Harley Quinn - Histrionic Personality Disorder

Histrionic Personality Disorder refers to the excessive need for attention and tends to morph into inappropriately seductive behavior as an adult. People experiencing this disorder exhibit unpredictable and erratic behavior with a side of 'drama-queen' antics. The most notable symptom, however, is that such people are easily influenced by others; much like the Joker's influence on her. Does that sound like Harley Quinn to you? Pretty much.

4 Two-Face - Dissociative Identity Disorder

Dissociative Identity Disorder is a mental illness that is distinguished by the perpetuation of two or more personality states. A person experiencing this disorder also undergoes gaps in memory.

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After being left with a half-burned face, you see Two-Face slowly descending toward criminal behavior, questioning the very boundaries of good and evil. This is when he begins to fully embrace his "Two-Face" persona. With the flip of a coin, he chooses whether to be charitable or to commit crimes.

3 Catwoman - Antisocial Personality Disorder

People suffering from Antisocial Personality Disorder exhibit a sheer lack of remorse for having deceived and manipulated others into getting what they want. Catwoman is a top-class burglar, with her 'art' dating back to her teenage years. This long-standing pattern of violating rights and exploiting others for personal gain is an immaculate portrayal of someone with an Antisocial Personality Disorder.

2 The Riddler - Autism Spectrum Disorder

More than your average textbook weirdo, The Riddler is a patient of Autism Spectrum Disorder. Categorized by inappropriate social interactions, severe behavioral disturbances, and obsessive habits, this disorder aptly explicates The Riddler's compulsion to ask riddles as well as his total lack of social skills.

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Although autistic behavior is typically not associated with violent criminal nature, it is possible that he was also a straight-up psychopath. That is also evident from the fact that he is never able to empathize with people and views everyone as the same; different from himself.

1 The Joker - Borderline Personality Disorder/ Pseudobulbar Affect

Saving the most complex case for last, The Joker is a true product of all of society's evils. It's common knowledge that people suffering from Bipolar Personality Disorder tend to exhibit strong abandonment issues. While there is no clear-cut origin of his father, it can be argued that The Joker never had him around during his childhood. Aside from his daddy issues, he often breaks into laughter uncontrollably and in the most inappropriate situations. This sort of erratic display is associated with Pseudobulbar Affect wherein the patient is often found exhibiting episodes of sudden laughter or crying. Unquestionably, it's the excessive physical abuse that he endured as a child that led to his mental demise, leaving him with nothing but a life of violent crime to turn to.

NEXT: 10 DC Villains We Can't Believe Batman Never Fought