I had a dream that an animorph lion kept chasing his completely human sister around trying to eat her because she refused to marry him. He would turn into a huge lion right before he was about to eat her but change back when they were outside. They ran through peoples houses, she sacrificed people, children, prostitutes and others to distract him but it only gave her a few second head start each time... It wasn't me, but at times, I saw through the sisters point of view and then third person... never his or anyone elses though. Also when he was human, the lion guy would always carry a package of diapers and a hat... what does this mean?
Based on the description of your dream I'd say you're suffering from some sort of psychotic delirium with morbid fascination with not only feline creatures but also juvenile sanitation devices. I'd suggest contacting your local pet shop immediately.
At first I thought you might be a shape-shifting shaman in World of Warcraft. But the diapers don't work there.
So I'm afraid we must lean just a bit toward the Freudian. Excuse me if I make the big assumption that you are an adolescent guy. It seems to me that the lion represents the physical urges that are becoming stronger and more demanding as your body matures. These include not only the sexual urges but also anger and a potential for physical violence that you have not felt before.
Your "sister" could symbolize both your efforts to control your self as well as your potential victim. That would explain sometimes taking her viewpoint.
The hat and diapers are really interesting. The hat is a literal depiction of the expression "keep a lid on it," as well as "keep your hat on." In other words, you know you need to maintain control until the time is right for powerful physical acts. The diapers are "just in case" you "mess up"! In other words, your human self - your responsible, mature self - is doing everything possible to prevent the disaster you feel will result when your physical urges break out of control.
Altogether this is a delightfully creative and expressive dream - well done!