The Joker is one of the most interesting and popular villains in comic book history. If you want to act like him, start by teasing people and acting mischievous. Work on talking and laughing like him to make yourself even more convincing. Wear the Joker clothes and makeup style for the perfect performance.
Steps
Part 1 of 3: Behaving like the Joker

Step 1. Act naughty and make jokes
The Joker always has a trick or two up his sleeve. Carry joke objects with you at all times and hide them in strange places. Your shoes and sleeves are good places to hide tricks.
- Bring wind cushions, hand buzzers, disappearing ink, fake vomit, cheat dice, and whatever else you like.
- Visit a joke shop for ideas and buy any jokes you want. You can also order things online.

Step 2. Work with your minions to come up with evil plans
The Joker is cunning and intelligent. He always has plans, backup plans, and people doing the dirty work. Get a group of friends together to act as your minions and come up with a naughty plan.
For example, you and your friends can plan an ambush at your sister's blanket fort

Step 3. Be unpredictable to make people nervous
The Joker does and says things just because he wants to do them and doesn't care about the consequences. Introduce a bit of chaos into your life by acting unpredictable when you are with friends and family. However, don't do anything dangerous.
For example, when someone asks you a question, pretend they asked you something else and answer that question

Step 4. Make a lot of weird jokes
The Joker continually jokes and says weird and funny things to others. Do the same. Laugh hysterically as the others look on in confusion. Then laugh louder. The Joker loves to confuse people and make jokes that only make sense to him. In the comics, it says things like the following:
- "Life is a bowl of cherries … and this is the bottom line!"
- "I'm not crazy at all! It's just that my sanity is different!"
- "More powerful than a locomotive … and just as subtle" (talking to Superman).

Step 5. Never take anything too seriously
Always look at the happy and fun side of everything. Keep a humorous attitude in life and don't let anything get to you. No matter what happens, even if it is something negative, take it as the Joker, with a smile.
Part 2 of 3: Look Like the Joker

Step 1. Wear distressed purple and green clothing
The Joker always wears nice clothes that are worn, like scruffy suits. He mainly wears purple and green clothing. Try buying a few weird suits, ties, and other "dress-up" things at a thrift store. Add some rips and stains to the clothing to make it look worn.

Step 2. Put on the Joker makeup
If you dress like him, you can't skip the makeup. Smear your entire face with oily white paint. Add oily black paint around the eyes. Use bright red lipstick to create an exaggerated smile around your lips.
- You can buy oily paint at costume stores.
- Take care that the paint does not get in your eyes while you put it on.
- If you want to look like Heath Ledger's Joker, put on some lipstick and sloppily apply makeup.

Step 3. Practice the Joker posture and gait
This depends on which one you want to act like. Heath Ledger's Joker walks hunched over. Jack Nicholson's one stands up straight, but in a very comical way. Pick whoever you want to be, then practice his posture and the way he walks.
Check out some YouTube videos if you can't remember some of the details

Step 4. Pick some strange habits and repeat them incessantly
The Joker has a lot of weird tics, like licking his lips continuously. When you speak, emphasize certain things by pausing and licking your lips before finishing the sentence. You can also smile strangely at the wrong times.
Part 3 of 3: Sound like the Joker

Step 1. Speak briefly and get straight to the point
The Joker does not ramble. He speaks in short sentences and often says strange things. Try saying weird random things and then laugh hysterically.
The best way to get your voice right is to practice while watching the movie

Step 2. Change the volume of your voice randomly
Usually the Joker speaks in a low, husky voice. Sometimes he yells random things to surprise people. Try to say something in a light whisper. Then yell out some random sentences and with wicked emotion.

Step 3. Practice the Joker 'disturbing laugh
The Joker laugh is a sort of hoarse laugh that sounds quite upset. Before you laugh, breathe out first instead of inhaling like most people do. This will help you sound hoarse. Then laugh long and hard. Think about how witches laugh in movies. Try something like that, but crazier.

Step 4. Be charismatic when talking to people
The Joker is confident and speaks without fear. This gets the attention of others. Then use words, looks, and gestures to keep your eyes on him. Listen to people when they talk and pretend interest in what they say. Lean in to whisper a weird response to them, then laugh out loud before leaving the room.