Mania in simple terms means being 'crazy' or 'mad' or obsessed about something. Mania is an obsession, excess enthusiasm, excitement and desire for something. There are several manias people suffer from in today's life, however following list of 10 manias are very weird but many people suffer from it.

1. Onychotillomania - It is a kind of mania where a person has compulsive desire to pick the fingernails and or toenails. Biting the nails is different than picking the nails. Many of us have the habit while biting their nails while watching the sports or if they are anxious about some thing. We cannot consider this as mania as this is not an obsession. The obsession to pick the nails is so severe in people with Onychotillamania that they don't even realize that the nails are deformed due to biting. Such kind  of mania mainly occurs in psychiatric disorder like obsessive compulsive disorder, or seen in people who are going through an immense psychological stress. Several research studies indicate that some people experience pleasure or feel relax after picking the nails! 
2. Pyromania - This is one of the horrible and scary mania. Think about a situation where one sets the fire only for personal gratification! How scary that would be? Pyromania is an urge to deliberately start the fire, such people fail to resist their desire. Pyromaniacs are different from those who set the fire for criminal, personal and monetary purposes. People suffering from Pyromania purposefully set the fire on multiple occasions in order to get intense fascination and pleasure from the fire.                                                                                  Now you might think why would anyone do such crazy things? What would be the reasons for doing such act? There are several reasons for this kind of weird mania. The first most reason is the buildup stress and emotions over the long period of time. Other factors like sexual abuse at younger age, lack of attention from parents or loved ones, and desire to take revenge contribute to the development of this mania. 
3. Kleptomania - Kleptomania is an inability to resist the urge to steal. The urge to steal is not for the personal use or for financial gain but its a severe desire to steal that a person cannot resist. You can call Kleptomaniacs as a 'thief', however such people are different that 'ordinary thief' as ordinary thief deliberately steal things for personal or monetary use whereas such intentions are not seen in Kleptomaniacs. People suffering from Kleptomania are usually shoplifters, they steal from public places, from know people's house and even from their own house. However they do not make use of those stolen items; they may donate or return them back. Once they realize that they have stolen something they feel guilty but they are unable to control this obsession for certain period of time. 
4. Oniomania - Strong and impulsive desire of shopping or buying is 'Oniomania'. In other words it is also called as 'Compulsive Buying Disorder'. People suffering from Oniomania buys excessive and expensive stuffs which may not be necessary for them. Due to such behavior many people go into debt, and financial losses. This behavior may sound very similar with 'Shopaholics' . In shopaholics people buy many unwanted stuff but the desire does not last for longer time. Oniomaniacs will buy anything, anytime to counteract the feeling of depression and loneliness through shopping which makes them feel relaxed. Oniomania is like an eating disorder where people eat with any control over eating; even though they want to stop eating they fail to do so. 
5. Dromomania - In simple terms it is also called as ' Wanderlust'. People with Dromomania has psychological desire to wander and travel long distances. We all love travelling but after certain period of time we all get tired of it and want to stay at one place quietly, however this is not the case with Dromomania. These people travel crazily. They make spontaneous decision of travel and easily move from one place to another, sometimes they even forget that they traveled to a place before. Such people cannot remain at one place for longer time; they are excited to travel and the greatest motivation for them is making more money for your journey.   
6. Ergomania - It is popularly known as 'workaholism' which means people enjoy their work and compelled to do lot more work than required. Such people may not be hardworking but they like to be constantly into the work. Such people would work from 8 am to 4 pm, volunteer in the evening, work during weekends and during vacation time.  Such people neglect their families and social life. This obsession to work make them vulnerable to many health conditions.Why do people like to be workaholic? because it gives them satisfaction of doing something useful, gives them more money and more confidence. 
7. Mythomania - Have you seen people making up things or constantly lying? They can be suffering from Mythomania, which is a psychiatric disorder where an individual is compelled to lie, or exaggerate the truth; he does not even realizes he is lying. Such people are unable to differentiate reality and fantasy. Many scientist believe the abnormal brain structure can be the cause of urge to lie. Usually people with low self-esteem would lie to make themselves feel important and attract the attention of people by making up the stories.