Extensions—special tools and features you can add to Firefox—can make your browser do very serious things like help protect your online privacy, block ads, help with large media downloads, re-organize your bookmarks, and so much more.

But extensions aren’t just for big jobs. Sometimes the point is pointless fun. Let’s look at the lighter side of browser customization.

Want a little party every time you open a new tab? There are a bunch of extensions that make opening a tab tons of fun. Tabby Cat treats you to an animated kitty with each tab. Give them little gifts for added adorableness. YOU CAN EVEN PET THEM!

New tabs can drop knowledge, too. Random Unusual Wikipedia New Tab presents you with an interesting Wikipedia subject with each page startup. This never fails to delight. Why, just today we learned all about competitive bog snorkeling.

New Tab Game delivers a different casual game with every new tab (plus a convenient, clickable list of your most visited sites). All the games are super simple to grasp and play right away.

One of the most popular casual games of all time—Flappy Birds—can nest right in your browser. Be forewarned, though, this is a game that even its own creator abandoned because he felt it was too addicting!

Sometimes even games require too much energy when you want to relax. For occasions when you just want to kick back with some YouTube entertainment, check out Magic Actions for YouTube. This extension puts a load of cool YouTube customization features right into Firefox—automatic HD viewing, annotation blocking, cinema mode, mouse-wheel volume control, video effect filters, and much more.

How about some music? TuneYou Radio pipes in grooves from more than 50,000 radio stations all over the world.

What if you could time travel and send your future self a bookmark from the past? Without bothering to squeeze yourself through a wormhole in space-time, you can do just that with Time Capsule. This extension lets you take any bookmarked page and set a point in time in the future for it to automatically open in Firefox. Hours, days, months—up to a decade into the future!

That’s probably enough fun for one blog post. But if you’d like to continue exploring extensions and themes for Firefox, please visit addons.mozilla.org (AMO).