You have to go on CP and go to the new stage with superheroes you need to be a member to get into the 'special place' where you can get the costumes.
Chat with our AI personalities
You have to buy the toy.
At the fall fair
get better at life.
It is possible to be a large penguin with WPEPRO, Penguin storm, and with a costume.
Just wait till club penguin releases it again! Hope this helps!