Last Updated: 22 Dec 2017

CryptoKitties launched in late Nov 2017, and within a week it had taken the world by storm, flooding the Ethereum transaction network and generally causing a ruckus as kitties are wont to do. This post will give you a brief introduction to the beanie babies (/neopets) of this generation, and a step-by-step guide on how to get your very own CryptoKitty. Prepare to get your paws wet!


There’s tons to learn in this post. To help you remember, check out my app Harvest: Take Notes and Learn Passively. It uses a memory algorithm called spaced repetition to help you remember notes just like this summary: summary

Table of Contents

What Are CryptoKitties?

CryptoKitties are digital cats that live purely on the Ethereum blockchain (refresher on blockchain). They are collectibles that you can buy, sell, and best of all, breed to create new kitties. When you own a kitty, no one can take it away from you (not even the CryptoKitty company) since your Ethereum address owns it and only you have the private key.

The whole point of CryptoKitties is not only that they are beautiful digital kitties that you can admire and collect (maybe this is the whole point); you can also breed any two kitties together and create an entire unique new kitty, with its own “cattributes” and name.


CryptoKitties are each part of a “Generation” — which just means that the kitties that were magically created and without parents are “Generation 0” and every subsequent breeding from these kitties are “Generation +1” of the youngest of the parents.

Generation 0 + Generation 0 = Generation 1
Generation 0 + Generation 1 = Generation 2
(since youngest parent is Generation 1)

genesis kitty

Genesis Kitty (the very first!)


“Cattributes” (cat attributes) are what uniquely define a kitty. These describe everything about your kitty, including color, eyes, eyebrows, mood, and patterns. It’s important to remember that these are the phenotypes (physically manifested) of the kitty however; each kitty also carries genotypes (not necessarily physically manifested) in its DNA (ie. 256-byte genetic code) that can be manifested in the future in its offspring. What this means is that just because two parents are “orangesoda” does not mean an offspring will necessarily be “orangesoda”, and the offspring can even have cattributes that neither of its parents have!


Cattributes for Founder Kitty #2

Various community resources have sprung up including one called CryptoKittydex. That page gives a great overview of the relative rarities of different cattributes; “totesbasic” is the most common, and “googly” is the least. Generally the rarer the cattribute, the more valuable it will make your CryptoKitty.



The last aspect of a CryptoKitty is its “Cooldown”. The cooldown represents how long it takes for a kitty to recover once it breeds; the faster the cooldown, the sooner the kitty can breed again. Naturally if you want more kitties you would want a faster cooldown kitty. General wisdom is that the earlier Generation the kitty, the faster the genotype of its cooldown.


Founder Kitty #3 is fast!!

Kitty cooldown gets slower and slower the more it breeds; so if you start out as Fast, then each time your kitty breeds it becomes incrementally slower and may or may not drop a notch. Newborn kitty cooldowns start off based on the Gen of its parents. Here’s a super handy guide courtesy of Reddit:

cooldown guide

How To Buy Your Own CryptoKitty

Alright now let’s get our very own CryptoKitty! Remember that all of the CryptoKitties live on the Ethereum blockchain, so the only way to buy, sell, or breed them is through an Ethereum transaction. Luckily we can use any browser to do this.

1. Create A MetaMask Account

We’ll use Chrome browser as the example for this guide. The first thing we have to do is install the MetaMask extension. This extension allows us to access the Ethereum blockchain directly from our Chrome browser without having to deal with syncing the blockchain or any of that business.

metamask download

After you install the extension, open it up and accept your away through the terms of service and legal nonsense. Who reads those anyway?? You’ll have to scroll all the way down on one of them in order to proceed.

If you have a MetaMask account from before, you can import your keys to restore the account. Otherwise, you will be prompted to create a new account with a new password of at least 8 characters. Create that and keep it in a safe place.

metamask password

You will also get a bunch of random words after you create your account. Treat this string of words as your “seed” that can regenerate your account in case you lose your password. So a password for your password if you will. Keep this in a safe place as well.

metamask seed

2. Buy ETH and Send to MetaMask

Now we are ready to get some ETH in order to buy some kitties!

First get a sense of how much ETH you want to spend; you can browse the CryptoKitties marketplace to see the price (in ETH) for each kitty up for sale. The sales work in a decaying price format; each one starts at a certain price, and decays linearly over time to an end price over the duration of the sale. So a kitty that starts at 2 ETH and ends at 1 ETH over 24 hours will be available to purchase for 1.5 ETH after 12 hours (if no one buys it) and then 1 ETH at the end of the 24 hours.

kitty marketplace

Once you’ve figured out how much ETH you need, it’s time to get some. If you already have ETH, feel free to skip over this part. MetaMask has an option that allows you to buy ETH directly from Coinbase; you can also use my link:

Help me help you! Sign up for Coinbase using my referral code (already linked) and we both get $10!

coinbase logo

On Coinbase, you’ll be able to purchase ETH using conventional fiat methods including PayPal, Bank Account (US), and Credit/Debit Card; each has different buying times and limits, generally the longer the buying time the higher the limit.

coinbase payments

Once you buy some ETH, tab on over in your Coinbase account to “Send” and pop in your MetaMask account address that you created in the previous step. It should start with “0x” and you can copy the address to clipboard directly from MetaMask from the dropdown menu.

metamask address

Wait a little bit of time for the transaction to process and you should now see some ETH in your MetaMask account!

3. Create a CryptoKitties Account

Now, while signed into MetaMask, you can navigate to the CryptoKitties site and the Sign In page where you’ll have to create an account with email address and nickname for yourself. Everyone will see your nickname! But you can change it later.

kitty signin

4. Purchase a CryptoKitty

The moment is here. Go back to the marketplace now and find the kitty of your dreams. Whether it’s Gen 0 or Gen 18 everything is there for the taking. You can sort by Youngest (Gen 0 first), Oldest (Gen latest first), Cheapest, and Most Expensive to make things easier. Once you’ve found one, click “Buy” and you’ll be prompted with a final confirmation page. Click “OK, buy this Kitty” to initiate the transaction.

kitty buy

If everything worked, then MetaMask will pop up one more confirmation screen with a bunch of numbers like Amount, Gas Limit, Gas Price, Max Transaction Fee, and Max Total. For the most part you can leave these as their default, and just make sure the “Max Total” is close to what the listed kitty price was for.

Note: Per this reddit thread, many txs can fail because other people are bidding, which will cause you to lose some Gas. Thus: look on page 5 onward for the lesser trafficked kitties, and use the current “Gas Price SafeLow (Gwei)” amount listed on ETH Gas Station to set the “Gas Price” if it is too low.

kitty buy metamask

If you have enough Ether (unlike my account here), then you click the big green button to “Submit” and initiate the transaction officially on the Ethereum blockchain. If all goes well, then you did it! You are now a proud owner of a CryptoKitty.

If you are having transaction issues, follow the fix from this reddit post which entails swapping out the MetaMask node for one that is less crowded.


With a CryptoKitty in hand, you can now put it up for siring, breed it with another kitty, or just admire it and brag to your friends. Treat it well and maybe one day your kitty will be worth many more ETH.. who knows!?

The blockchain was virtually made for cats after all.

Give Marshmeollow (**Gen 1 cloudwhite**) some love!
Guaranteed some white & fluffy offspring.


Useful Links

Liked this tutorial? Any tips are greatly appreciated!
ETH: 0x95c81f04d214330F687EBa412fF4fbb26ca9d708
BTC: 15kR6ty4TLi5bxm2r6gUxSJvsFQkNEwxf8