To see a kangaroo in your dream refers to maternal and paternal protection. You may be expressing your nurturing and mothering nature. Perhaps, you are being too overly protective. Alternatively, a kangaroo symbolises aggression. If the kangaroo is hopping, then the dream is analogous to how you jump from one thing to another. You lack the ability to stick to one thing.
To dream that a kangaroo attacks you, indicates that your reputation is being called into question.