Karli is a character from the children's television series Sesame Street. She is a green, friendly monster who was introduced to help teach children about emotions and mental health. Karli often shares her experiences and feelings, encouraging young viewers to express themselves and understand their own emotions. In the show, Karli has a unique backstory involving her foster care experience, which helps to address important social issues. She interacts with other beloved characters like Elmo and Big Bird, promoting themes of friendship, kindness, and resilience. Karli's presence aims to create a supportive environment for children facing similar challenges.