Seeing a cartoon world in your dreams or seeing cartoon-like people suggests that your unconscious is sending up messages which are telling you something about the way you perceive the world.
The cartoon people, or cartoon characters, suggest that you may perceive yourself and those around you as comical or as not having much validity or seriousness. Your perceptions may be somewhat off due to your inability to look at the way things really are. Your mind’s eye distorts things so that you are more comfortable with what is going on around you.
If your world is full of stress and this dream made you laugh, consider the compensatory nature of it. In your dream you may be able to obtain moments of lightheartedness and fun.... The Bedside Dream Dictionary
Often an erotic dream. In the case of women, it points to their feminine side or to childhood. What is addressed here is usually the lightheartedness of a child’s life. In the case of both men and women, it symbolizes the feminine side of the dreamer. When the soul appears in a dream in the form of a girl, it usually points not only to the natural lively and innocent side of you, but also to the undeveloped and childish side.... Little Giant Encyclopedia
One who refuses to accept responsibility for having chosen to live in this reality; one who acts out primal urges of man. Also, lightheartedness; acting on the spur of the moment without thinking.... The Dream Books Symbols
The otter as a symbol is all about joy and playfulness. As a creature that lives in water, the otter connects to the feminine principle and being grounded in the earth. Otters play in the waters of emotion and unconscious expression, and when they appear in a dream, they remind us that the aspects of life that are emotional in nature are to be approached with lightheartedness and reveled in.... Complete Dictionary of Dreams
Humor in a dream is a good indication of lightheartedness and release from the tension that may have surrounded some issue. There is, however, also a negative side of humor, such as when someone or something is derided as “a joke.”... Dream Symbols in The Dream Encyclopedia