How do you get the propeller cap on Club Penguin?

I'm sorry but the propeller cap on Club Penguin is not available at this time, but it may be available in the future. I have it on one of my really old Club Penguin accounts that I don't use much anymore which is also a nonmember, the propeller cap is available to non members. And so far, there are only the red and blue propeller caps.

Note:They are at the April fools parties and also in rhe april fools party 2012 there is a blue propeller cap.

improved on Jun.16,2012