Party Hats are head items which are given during Anniversary Parties. They are always pointy at the top and covered in different colored stripes. Party Hats are usually found at the Coffee Shop, where all players can obtain them. All of them are available during the time line of the party - which usually lasts for a day or a few days - and are never available again. The only exceptions are the 5 Year Celebration Hat and French 5th Year Party Hat, which are currently unlockable.
Orange and yellow are the most common colors in the hats, appearing in six out of the nine hats.
Orange and yellow are the two colors of the 2nd Anniversary Hat.
When wearing a Party Hat (apart from the 7th, 8th, & 9th Anniversary Hat) and go to the Fire Dojo or Water Dojo, Sensei will comment "I see you're wearing an Anniversary Hat. I like pointy hats."
The 6th, 7th, and 8th anniversary hats have had some relevance to the respective years they represent in Club Penguin. The 6th Anniversary Hat was orange, green, black, and purple because it was the first Anniversary Party to take place at the same time as the Halloween Party. The 7th Anniversary Hat had the colors of Club Penguin's new logo that was revealed in the same month. The 8th Anniversary Hat has the colors of the Rainbow Puffle, because it released earlier that year.