It can be seen on the 1 year anniversary login screen.
This item is frequently called the "Beta Hat".
It's the only bait item that was previously available to everyone.
It has an item ID of 413.
Former Club Penguin staff member Screenhog who designed the item deliberately chose colors that he considered 'tacky' in an attempt to make the item less desirable in the future. This failed however, with the item remaining among the most sought after in all of Club Penguin and more recently in Club Penguin Rewritten.