Sure, why not?
Just one rule about shapeshifting.
We cannot shapeshift into one another. I can't turn into you, and you cannot turn into me. This will get too confusing.
Otherwise, feel free to look up the rules and plot (on the first page), read the story, and add your part.
“…Judge not what a man has done, but judge what he could have done if he was a different bloke altogether. For art thou a leper? And a leper can changeth his spots…” --Rudy Wade, Misfits (Series 4, Episode 8)