My friend introduced me to the Tabby Cat cult club.
It’s a browser extension for Chrome and Firefox which shows you a cute animal as your new tab page.

Essentially, as you open more tabs , you unlock new toys (and characters *).

Snooping around the source code (Firefox) we can see this

function shouldPickNewGoody(visits) {
	if (visits === 1) {
		return true;
	} else if (visits % 200 === 0) {
		return true;
	} else {
		return Math.random() < 0.005 ? true : false;
	}
}

Every 200 visits, you get a new goody.
Otherwise you have a 0.5% chance of getting a new goody

But I want it nowwwwww

On their wiki page there are some hacks to unlock all the toys (and characters *).
But you can also just run getNewGoody() a bunch of times in the browser console!

Characters

The Firefox version is a stripped version of the more feature-packed Chrome version.
Namely, only the Chrome version has extra characters - and you have to pay to unlock them. (Only $1 USD!)

No doggos :(((

I don’t use Chrome as much anymore, so paying or not, I still won’t be able to use other characters. Ah well.
Possibly if I had time, I would have a peek into the source code to figure out how to circumvent the payment.
But supporting the developers is a good thing! More money = more toys and characters = more fun!