Mutations are the fastest way to make one pet earn several times more money in Steal an Egg. A Rainbow pet earns 3.5 times its normal income, and a big egg can multiply that again. This page lists every mutation in our database, explains how each one is obtained, and shows the size and weight formula the wiki documents, with real numbers.
All numbers come from the Steal an Egg Wiki and the official update notes. Income results are estimates based on the wiki's formula, not in-game measurements.
All mutations and their multipliers
There are 8 mutations with a documented multiplier. The multiplier is applied to the pet's base income, so a pet that makes $100/s with Golden (2.5x) makes $250/s before size is counted.
| Mutation | Income multiplier | Hatch roll weight | How you get it |
|---|---|---|---|
| Rainbow | 3.5x | 1 of 100 | Random roll when an egg hatches |
| Parasite | 3x | Not in normal rolls | Parasite Egg from the feeding event (Hungry Frog) |
| Fractured | 2.75x | Not in normal rolls | Mutation Shard from the Rift Boss Shop (10% chance) or Boss Mastery eggs |
| Scrambled | 2.75x | Not in normal rolls | Scrambled Mutation from Dr. Scramble's Experiment Shop (10% chance) |
| Golden | 2.5x | 4 of 100 | Random roll when an egg hatches |
| Spirit Bloom | 2.5x | Not in normal rolls | Sakura Incubator in Cherry Blossom |
| Bloom | 1.25x | Not in normal rolls | Sakura event (Cherry Blossom) |
| Silver | 1.2x | 6 of 100 | Random roll when an egg hatches |
The full list with images is on our mutations page. If you only remember one thing: Rainbow is the best multiplier we have data for, and Silver is the weakest.
Hatch-roll mutations: Rainbow, Golden and Silver
Three mutations can appear on their own when an egg hatches. You do not need any item for these. Every hatch gets a roll, and with some luck the pet comes out colored.
Roll weights out of 100
The wiki gives each color a roll weight "out of 100". Read as a chance, that is about 1% for Rainbow, 4% for Golden and 6% for Silver on each hatch.
- Rainbow (3.5x): an animated effect that keeps changing colors. Weight 1, so roughly one hatch in a hundred.
- Golden (2.5x): shiny gold with coin particles. Weight 4.
- Silver (1.2x): silver with metallic reflections. Weight 6, the most common of the three.
This also answers a common question: the rarest roll you can get from a normal hatch is Rainbow, and it is also the one that pays the most.
Mutations from consumables and events
The other five mutations never come from a normal hatch roll. You get them through events, shops or special eggs. Most of them work on an egg that is already in your pen.
Fractured: Mutation Shard from the Rift Boss Shop
Fractured (2.75x) arrived with Update 3, the Rift update. A Rift opens somewhere on the map every 30 minutes. Go inside, beat the Overlord and you earn Boss Tokens. You spend those in the Boss Shop.
The Boss Shop sells temporary boosts and a consumable Mutation Shard. This is the "Mutation Consumable" many players search for. It has a chance to apply the Fractured mutation to an egg already sitting in your pen. Our sources do not list its price in Boss Tokens.
There is a second way. Every Overlord you defeat gives Boss Mastery Points, and the Mastery track includes eggs that already come with the Fractured mutation. See the Rift Event page for the banners and rewards.
How to use a Mutation Shard on an egg
- 1Beat the Overlord in a Rift to collect Boss Tokens.
- 2Buy the Mutation Shard in the Boss Shop.
- 3Walk up to an egg in your pen. It can be growing or fully grown.
- 4Interact with the egg to use the shard.
- 5The shard has a 10% chance to apply the mutation to that egg.
Scrambled: Dr. Scramble's shop
Scrambled (2.75x) has a poison-like look. It came with Update 5. Every 30 minutes Dr. Scramble's drones invade the map. Destroy them to collect Samples, then spend Samples in the Experiment Shop.
The shop lists the Scrambled Mutation at 475 Samples, one use, with a 10% chance. It works like the shard: you apply it to an egg. More details are on the Dr. Scramble Event page.
Parasite, Spirit Bloom and Bloom
- Parasite (3x): the second best multiplier. It is not a hatch roll. It comes from its own Parasite Egg, earned through the feeding event. In Update 2 (Hungry Frog), parasites attach to eggs across the map, and you feed them to the Hungry Frog.
- Spirit Bloom (2.5x): a green spirit effect. Update 1 called it "extremely rare". It comes from the Sakura Incubator in Cherry Blossom.
- Bloom (1.25x): cherry blossom petals. It also belongs to the Sakura event, not to normal hatching.
To unlock the Sakura Incubator, hatch a Crane from a Cherry Blossom Egg and bring it to the ancient Sakura tree. Every 30 minutes the Great Bloom fills the biome with Sakura Crystal Trees. Break them, collect Sakura Crystals and deposit them in the incubator to mutate your eggs.
Update 2 also mentions a limited-time Monstrous Mutation, a rare drop from Monster Chests for monsters from Titan Temple. Its multiplier is not documented.
New in Updates 7 and 8: Enchanted and Nitro
The two newest updates added mutation consumables. Our sources confirm how to get them, but not their income multipliers. We will not guess a number.
| Consumable | Update | How you get it | Success chance | Multiplier |
|---|---|---|---|---|
| Enchanted Mutation | Update 7 (Enchanted Forest) | Catch butterflies during Butterfly Bloom and trade them | 100% | Not documented yet |
| Nitro Mutation | Update 8 (Mounts) | Spend Trophies from the Nitro Race | Not stated | Not documented yet |
| Mutation Shard (Fractured) | Update 3 (Rifts) | Boss Shop, paid with Boss Tokens | 10% | 2.75x |
| Scrambled Mutation | Update 5 (Dr. Scramble) | Experiment Shop, 475 Samples | 10% | 2.75x |
Enchanted Mutation. In the Enchanted Forest you need 50B Speed to find the Wisp. Help him back to the Enchanted Tree and he unlocks it for you. Inside, grab a Butterfly Net, catch butterflies during Butterfly Bloom and exchange them for the Enchanted Mutation. The official notes say it has a 100% chance of working, which makes it the only consumable that never fails.
Nitro Mutation. Update 8 added the Nitro Race. A race starts every 30 minutes, and you earn Trophies by competing. Trophies buy boosters, Nitro Mutation consumables and an exclusive bat. The notes do not give a success chance or a multiplier.
Size and weight: the second multiplier
A pet's size is a separate trait from its color. The pet card shows it as a weight in kg. Size is rolled apart from color when the egg hatches, so you can get a Golden pet that is small or a huge pet with no color at all.
Bigger eggs hatch pets with higher value. The catch, as the wiki puts it, is that heavier eggs make you slower while you carry them.
The wiki's weight formula
Every pet has a hidden base weight. The ratio is the pet's actual weight divided by that base weight. According to the formula the wiki documents:
- Ratio up to 125x: income = base income x ratio^(37/60) x mutation multiplier
- Ratio above 125x: income = base income x mutation multiplier x ratio^(2/5) x 125^(13/60)
Both parts give the same value at exactly 125x, so the curve has no jump. The wiki marks its own calculator as beta, so treat the results as estimates.
The 125x diminishing-returns point
Below 125x, extra weight pays off well. Past 125x the gain per kg gets smaller. Here is the size multiplier at different ratios, calculated with that formula:
| Weight ratio (actual / base) | Size multiplier | What it means |
|---|---|---|
| 1x | 1.00x | Base weight, base income |
| 10x | 4.14x | Ten times heavier, about four times the money |
| 50x | 11.16x | |
| 100x | 17.11x | The wiki rounds this to ~17x |
| 125x | 19.64x | Diminishing returns start here |
| 200x | 23.70x | The wiki says ~23x |
| 1000x | 45.12x | The wiki says ~45x |
Going from 125x to 1000x makes the egg eight times heavier but only raises income by about 2.3 times. Bigger is still better, just less so.
Putting it together: final income examples
The wiki writes the full rule like this: Final Income = Base Income x Mutation(s) Multiplier x Size Multiplier. Its own examples use a $100/s pet:
- Normal: $100/s
- Golden + Giant: 100 x 2.5 x 3 = $750/s (7.5x total)
- Rainbow + Huge: 100 x 3.5 x 5 = $1,750/s (17.5x total)
Now a real pet. Kitsune is the Divine of Cherry Blossom, with a base income of $1.8B/s and a base weight of 260 kg. These are estimates from the formula:
| Kitsune weight | Ratio | Mutation | Estimated income |
|---|---|---|---|
| 260 kg | 1x | None | $1.8B/s |
| 260 kg | 1x | Golden (2.5x) | $4.5B/s |
| 520 kg | 2x | None | $2.76B/s |
| 2,600 kg | 10x | None | $7.45B/s |
| 2,600 kg | 10x | Rainbow (3.5x) | $26.1B/s |
| 26,000 kg | 100x | None | $30.8B/s |
| 26,000 kg | 100x | Rainbow (3.5x) | $107.8B/s |
Two lessons stand out. A 100x Kitsune with no color earns more than a 10x Rainbow Kitsune, so size matters a lot. And a mutation is worth the most on a pet that is already big and rare, because it multiplies everything else.
Use the income calculator
You do not have to do this math by hand. Our income calculator uses the same wiki formula. Pick a pet, type its weight in kg and choose a mutation, and it shows the estimated $/s.
- 1Open the income calculator.
- 2Choose the pet. Its base income and base weight load automatically.
- 3Enter the weight shown on the pet card.
- 4Pick the mutation and compare the results.
If you want the theory behind it, the sizes and weight page and the income and stacking page have the original wiki explanations.
FAQ
What is the best mutation in Steal an Egg?
By multiplier, Rainbow at 3.5x is the best mutation in our data, followed by Parasite at 3x. Fractured and Scrambled come next at 2.75x each.
What does the Mutation Consumable do?
The Mutation Shard from the Rift Boss Shop has a 10% chance to apply the Fractured mutation (2.75x) to an egg in your pen. It works on growing and fully grown eggs.
How rare is the Rainbow mutation?
The wiki gives Rainbow a roll weight of 1 out of 100, so about 1% of hatches. Golden is 4 out of 100 and Silver is 6 out of 100.
Does egg color change income?
No. According to the wiki, egg colors only change how the egg and pet look. Size and rarity decide income, so look at the egg's shape and size.
How is pet income calculated?
Final income equals base income times the mutation multiplier times the size multiplier. The size multiplier follows the wiki's weight formula, with diminishing returns above 125x the base weight.
What does the Enchanted Mutation do?
It is a consumable from Butterfly Bloom in the Enchanted Forest with a 100% chance of working. Its income multiplier is not documented yet.
