"Doo doo hair" refers to a hairstyle that is matted, tangled, and often covered in dirt and debris. It is commonly associated with people who are homeless or living in poverty, and can be a sign of neglect or mental illness.
The term "doo doo hair" is often used in a derogatory or dismissive way, but it is important to remember that it is a condition that can affect anyone. There are many factors that can contribute to doo doo hair, including lack of access to clean water, mental illness, and substance abuse.