CryptoKitties History – The Birthing Fee

Many players, both new and old alike, may not realize that the CryptoKitties birthing fee has not always been 0.008 ETH.

So here is a quick walk through the history of the birthing fee:

Nov 28, 2017: CryptoKitties launches with a birthing fee of 0.001 ETH
Dec 3, 2017: Birthing fee increased to 0.002 ETH
Dec 4, 2017: Birthing fee increased to 0.015 ETH
Dec 11, 2017: Birthing fee decreased to 0.008 ETH

Historical References

🚨🚨🚨🚨 Due to network congestion, we are increasing the birthing fee from 0.001 ETH to 0.002 ETH. This will ensure your kittens are born on time! The extra is needed to incentivize miners to add birthing txs to the chain. Long-term solution will be explored very soon! 🚨🚨🚨🚨

2:13 PM – 3 Dec 2017



1:25 PM – 4 Dec 2017

❤️❤️ We have dropped the birthing fee from 0.015 ETH to 0.008 ETH. Happy breeding everyone! 🐈

11:28 AM – 11 Dec 2017


Ralf Putmans (DerpyBastard) has graphed these birthing fee values against the ETH/USD price to chart the breeding price in USD over time (from November 28th, 2017 up through April 14th, 2018):

Birthing Fee

The average breeding price in USD over this entire time period is $6.06. Since the distribution of cats is skewed, the average amount spent to actually breed each kitty would be slightly different. You could overlay the births/day to calculate that number.

If you want to delve into the data, then please check out the Google Sheet that Derpy created:

About the Author

This article was written by Byzantinist (a.k.a. Byzantine Kitty), who is an expert on digital cat genetics. As a passionate aficionado of 100% 🐎 Purebred cats, Byzantinist runs a 🐎 Purebred Siring Shop that can be found here:

If you have any comments or feedback, you can contact me at or on Discord @Byzantinist – 🐎 Purebred Sires#2992

All About Cattributes

UPDATE: My discussion about terminology with Alanfalcon has spurred the adoption of several new terms among the CryptoKitties staff, which you might see them use in the near future. Instead of dominant (D0) and recessive genes (R1/R2/R3), they might refer to active (A0) and hidden genes (H1/H2/H3) for normal cats and H0/H1/H2/H3 for fancy cats. In addition, they prefer classifying genes found in Generation 0 cats as Level 1 while Wingtips is a Level 3 gene (instead of using the “Tier” keyword).

Every cat has a cattribute/trait in 8 different categories which each has an impact on the visual appearance of the cat (except for Fancy cats). There are also 4 additional categories which are normally hidden.

If you do not understand basic CryptoKitty genetics, including how dominant and recessive genes work, then I recommend you start with some older CryptoKitties411 articles:

The 8 primary cattribute categories are:

  • Fur / Body
  • Pattern
  • Eye Color
  • Eye Shape / Type
  • Base Color
  • Highlight / Pattern Color
  • Accent / Secondary Color
  • Mouth

One detail that is often missed is that the background of the cat image is determined by the Eye Color of the cat.

There are also 4 additional hidden categories. Basic Wild genes do not seem to do anything but Tier 1 Wild mutations (e.g. Elk, Trioculus) are additional cattributes which are displayed and impact the visual appearance of the cat. At this time, it is not known what Mystery, Secret, and Unknown genes do, though there is plenty of rampant speculation of what they might do.

Fancy cats of a given type all have the same physical appearance though the background color does change depending on Eye Color. Fancy cats are assigned a numbered Fancy badge instead of having cattributes displayed. However, they still have relevant dominant and recessive traits which can be passed down to their offspring. And while none of their family or mewtation jewels are displayed, these still exist and can be passed down as well.

Not all cattributes are the same. Some are much rarer or more valuable than others. To help you better understand the nature of cattributes, here are some broad categories that are sometimes used. Most of these terms are used colloquially (instead of there being an official definition) so there may be slight differences in meaning or usage.

Normal / Base Traits

“Normal” often means the standard traits that do not fit in any of the other categories (not mutations, retired / discontinued, or founder traits).

Sometimes, “Base” trait is used to refer to all non-mutation traits (which may include retired / discontinued and founder traits). So Jaguar might be considered a “Base” trait but not a “Normal” trait.

Founder Traits

The first 100 cats are the Founder cats and they are each assigned a special Founder badge. Every Founder cat has the following genetic makeup for their dominant and recessive genes:

Fur: Himalayan, Munchkin, Ragamuffin, or Sphynx
Pattern: All Founders are 100% 🐎 Purebred Jaguar
Eye Color: Chestnut, Mintgreen, Sizzurp, Strawberry, or Topaz
Eye Shape: Crazy, Simple, or Thicccbrowz
Base Color: All Founders are 100% 🐎 Purebred Orangesoda
Highlight Color: Chocolate, Coffee, Lemonade, Royalpurple, or Swampgreen
Accent Color: Granitegrey or Kittencream
Mouth: Beard, Happygokitty, Pouty, or Soserious

Jaguar is a special case because among Generation 0 cats it can only be found among the original 100 founders. That means that any higher generation cat with a Jaguar gene is a descendant of at least one of the Founder cats.

Beard, Chestnut, and Simple are also notable cases because the only Generation 0 cats with dominant Beard, Chestnut, or Simple are some of the Founder cats. These genes may appear in non-Founder Generation 0 cats but only as recessive genes.

The traits listed above are collectively called Founder traits because they were present in those original cats. However, these genes can be found in other Generation 0 cats as well (except no Beard, Chestnut, or Simple as dominant and no Jaguar at all).

Since jewels were introduced much later, Founder traits are also notable because they do not have associated jewels (no diamond, gild, amethyst, or lapis). This can be an important consideration for players who want 8 jewel or 9 jewel cats.

There are also some additional jewel-less traits that are often considered Founder traits even though none of the 100 Founder cats technically had any of these genes:

Pattern: Luckystripe, Totesbasic F, and Totesbasic G
Base Color: Aquamarine, Greymatter, Salmon, and Shadowgrey

These cattributes can be found in some of the earliest cats (e.g. Bug Cat exclusive, 500-number cats) and other low number cats (e.g. Knight Kitty exclusives).

Retired / Discontinued Traits

Over time, some traits are phased out and no longer appear in new Generation 0 cats. These are referred to as “Retired” or “Discontinued” traits. Note that this is not an official designation. There is nothing to prevent Axiom Zen from including these genes again in upcoming Generation 0 cats but that has not happened so far.

An older list of Discontinued traits can be found here:

Discontinued Traits

I do plan to write an article in the near future to update the list of Retired / Discontinued Traits.

“Recessive” Traits

Recessive traits (which is different than recessive genes) is sometimes used to refer to traits that show up in recessive positions (R1, R2, or R3) in Generation 0 cats but are not expressed (D0) in any of those cats. The only way for these genes to become dominant is to breed the cats until gene swapping causes them to move into the D0 position.

The following traits can be found as recessive genes but not dominant in Generation 0 cats:

Fur: Chartreux and Savannah
Pattern: Calicool, Camo, Ganado, and Spock
Eye Color: Doridnudibranch and Forgetmenot
Eye Shape: Baddate, Otaku, Serpent, and Stunned
Base Color: Dragonfruit, Harbourfog, Hintomint, and Nachocheez
Highlight Color: Apricot, Barkbrown, Lilac, Poisonberry, Scarlet, Springcrocus, and Violet
Accent Color: Belleblue, Emeraldgreen, Missmuffet, and Peach
Mouth: Belch, Gerbil, Wasntme, and Whixtensions

Since it requires gene swapping to get these traits into a dominant position, it is rarer to see these cattributes expressed among low generation cats.

Furthermore, some recessive traits are rarer than others. For example, Chartreux can only be found in the R3 position of Generation 0 cats while Camo can be found in R2 or R3, and Otaku can be found in R1, R2, or R3.

As a result, for Generation 1 cats, a Chartreux is rarer than a Camo, which is rarer than an Otaku, which is rarer than a normal trait like Totesbasic or Granitegrey.

I will be going into more depth on these recessive traits in an upcoming article.

Mutation Traits

When two cats breed, certain pairs of traits can mutate into a new trait. For a primer on mutations, please take a look here:


Mutation traits simply do not appear in Generation 0 cats as dominant or recessive genes. So if you see something like this:

You know there is something wrong because Tigerpunk is a mutation and Otaku is a recessive trait so neither should be dominant in a Gen 0 cat. If you actually look at this cat’s genetic code, you will see that its Pattern is really Totesbasic F and its Eye Type is Thicccbrowz. So this is a front-end bug with the website.

It takes time for mutations to propagate so low generation cats with mutations can be extremely valuable and 🐎 Purebreds are not even possible until several generations have passed.

Note that there is some variance with terminology. Most people seem to refer to Cloudwhite as a Tier 1 mutation and Wingtips as a Tier 2 mutation. However, there are some people who refer to all base traits (non-mutations) as Tier 1, which would make Cloudwhite Tier 2 and Wingtips Tier 3. Furthermore, Alanfalcon has been advocating the use of “ascension” instead of “mutation.”

About the Author

This article was written by Byzantinist (a.k.a. Byzantine Kitty), who is an expert on digital cat genetics. As a passionate aficionado of 100% 🐎 Purebred cats, Byzantinist runs a 🐎 Purebred Siring Shop that can be found here:

If you have any comments or feedback, you can contact me at or on Discord @Byzantinist – 🐎 Purebred Sires#2992


How to Value Your Kitties

New Tool: Kitty Evaluator

It’s impossible to put a specific price-tag on a kitty because its value is determined by the market, but it is possible to identify what elements of kitties hold more value than others. For example…

  • When all other things are equal, low generation cats are more valuable than high generation cats.
  • When all other things are equal, mutations are more valuable than basic traits.
  • When all other things are equal, pretty traits are more valuable than ugly ones.

These comparisons can help you know what to look for in a kitty.

diamond princessValuable Components

The more of these components you have going for your kitty, the more valuable it will be. Low generation is easily the most important factor (if you intend to breed your kitties). If nothing else, PLEASE pay attention to generation.

Kitty Evaluator

But is there an easy way to evaluate your kitty’s traits? Why yes! So glad you asked!

Check out the new Kitty Evaluator! (Link in the sidebar.)

Final Takeaway

The most valuable kitties are usually those with multiple mutations in low generations.

To maximize your odds of getting mutations, use the Mutation Match-Up Tool.



Discontinued Traits

discontinued traits kitty 1
sizzurp, luckystripe, chocolate, and kittencream have all been retired

Update 3: Typo error on our end. Pouty is not discontinued yet. Apologies for any inconvenience!

Update 2: The other traits listed ARE truly retired. According to the CryptoKitties Community Manager, “Totesbasic re-appearing caused some worries, but I can promise you no traits other than totesbasic will come back.”

Update: Totesbasic_g is NOT retired.

Many players are unaware that cattributes are slowly being discontinued. These traits are no longer being released in Gen 0 cats, so the only way to get them is through cats that are already in existence. As time goes by, they will become more and more rare in low generation cats because they’ll be harder to produce (as the originator cats are likely Catatonic by now).

Not only will the discontinued traits become more rare, many of them will also be needed to create mutations with upcoming traits. For example, the eye color sizzurp is discontinued, but once the eye color with kai gene “5” is released, there will be a series of mutations that can happen only when combined with sizzurp. (To understand how mutations work, visit my post on Mutations and my post on All Possible Mutations.)

This might make sizzurp more valuable in low generations only.

In addition to being needed for mutations, discontinued traits will also likely be used in making fancies down the road. I personally think that as soon as new traits stop being released in Nov. 2018, the focus of the game will shift dramatically to fancies, fancies, fancies. If that happens, all these old traits will come into play in a much bigger way.

Here are the discontinued traits so far (to the best of my knowledge):

discontinued traits kitty 2
This kitty has 6 retired traits.
  • Himalayan (fur)
  • Ragamuffin (fur)
  • Cymric (fur)
  • Luckystripe (pattern)
  • Totesbasic_f (pattern)
  • Gold (eye color)
  • Sizzurp (eye color)
  • Googly (eye shape)
  • Crazy (eye shape)
  • Salmon (base color)
  • Aquamarine (base color)
  • Orangesoda (base color)
  • Chocolate (highlight color)
  • Violet (highlight color)
  • Kittencream (accent color)
  • Granitegrey (accent color)
  • Peach (accent color)
  • Saycheese (mouth)
  • Wild_4 and Wild_8 (wild genes)




How do Family Jewels work?

There are two kinds of Family Jewels: Mew-tation jewels and Cattribute jewels.

family jewels 2

Mew-tation Jewelsfamily jewels 4

These jewels are awarded to the first 500 kitties who initiate bloodlines for a trait. They do this by being the first in their family tree to either a) carry a new basic trait, or b) mutate into a new trait. The first kitty with a new trait gets a spinning pink diamond and the next 499 get lesser jewels.

family jewels 3

Cattribute Jewels

After the originator kitties claim their jewels, they get to pass them down to their descendants as cattribute jewels. Any descendant of an originator kitty receives the jewel if it also carries the trait. This means that jewels may skip certain kitties but then show up later in their children. Again, all descendants may claim their ancestor’s jewel as soon as they share the same trait. The descendants’ jewels will be the same color as their ancestor’s original jewel.

Think of is this way. When CryptoKitties launched, the developers released 100 Founder Cats that were all jaguars. Since then, there have been no other kitties released with jaguar genes. That mean, whenever you see a cat with the jaguar pattern, you know immediately that it has a direct tie to one of the Founder Cats. Family jewels mimic this exactly. If you see a kitty with a pink diamond next to “cloudwhite”, you know that it has a direct link to the very first cloudwhite kitty.

You can click on a jeweled cattribute to see the originator kitty that it came from.

Example: fj kitty

This kitty was one of the first 500 kitties to unlock the pattern “camo”. All of its descendants may receive its blue camo jewel if they carry the camo gene.

This kitty is also a descendant of the very first “slyboots” kitty, and a descendant of one of the first 100 “thundergrey” kitties. Etc.

family jewels 1

Will jewels make my kitty more valuable?

It’s hard to say right now because they’re so new. But I think it’s safe to say if there are two kitties with all other things equal, the kitty with more jewels will be valuable.

The mew-tation jewels will be more valuable than the cattribute jewels, and the most valuable jewel will easily be the pink diamond. The other jewels may end up as just eye candy, but the pink one will likely hold more significance.

Founder Badgesfounder badge

The Founder Cats did not get jewels, nor did their offspring. Poor jaguars. But the founders did get something else. They got badges. Aww.

What can I do with jewels?

You can collect them! If you breed jewel cats with other jewel cats, you can try to create kitties that have jewels next to ALL their cattributes. How fun would that be?!

Happy jewel collecting!


For more Kitty411 posts, click HERE.

Want to read more about Family Jewels and other new developments with CryptoKitties? Check out

ck banner 2

List of All Possible Mutations

Each trait has a “mutation pair” that, when bred together, has a small chance of mutating into a completely different gene. Here’s a guide on how to find all possible mutation combinations, even for non-visible genes and newly-released traits.

First, we need the Trait Chart. The Trait Chart shows all the discovered traits and their corresponding genetic codes. When a new trait is discovered, we simply look at the cat’s genes to see what code the new trait maps to.

Look at the chart. Do you see how the traits are divided into pairs? Each pair of neighboring genes can mutate.

What do they mutate to? Look at the right-hand column that says “mutates to”. It tells you what kai code the pair has potential to mutate into. For example, otaku+simple mutates to eye type ‘j‘, which is “fabulous” eyes.

trait chart explanation

When a new trait is released, you can immediately tell 1) what it will mutate with, and 2) where the new mutation will fall. For example, once we see eye type ‘1’ released, we know that you can breed it with “wonky” and that it will mutate into eye type ‘h’. AND THEN eye type ‘h’ can be bred with “alien” to mutate into eye type ‘q’. AND THEN eye type ‘q’ can be bred with “wingtips” to mutate into eye type ‘u’, which will be a tier-3 mutation!!

Ahhh. Beautiful, valuable mutation cascades. You gotta love ’em.

To learn more about mutations, visit THIS POST for a full explanation (including probabilites).

Also, to increase the value of your cats, try to stack mutations. Find a breeding partner for your kitty to maximize your odds by using this Mutation Match-Up tool.

Happy Breeding!
– Jodiferous