Steal An Egg Mutation Calculator
Updated · game data from the wiki as of 30 September 2026 · changelog
Short answer: Rainbow is the strongest hatch colour (×3.5, about 1 hatch in 100), then Golden (×2.5), then Silver (×1.2). A pet gets at most one of those three, plus possibly other mutations such as Bloom (×1.25) or Parasite (×3). The wiki's own calculator adds mutations: Golden + Bloom = 1 + 1.5 + 0.25 = ×2.75, not 2.5 × 1.25 = ×3.13. Which rule the game really uses is disputed, so this page shows both.
How mutations change income
Each mutation has a multiplier. These are the values and sources the community wiki gives (Mutations page, revision of 2026-09-20, and the wiki calculator):
| Mutation | Multiplier | How it's obtained (wiki) |
|---|---|---|
| Rainbow | ×3.5 | Hatch roll, weight 1 in 100 |
| Parasite | ×3 | Its own Parasite Egg (feeding event), not a hatch roll |
| Fractured | ×2.75 | Mutation Consumable on an egg, 10% chance |
| Scrambled | ×2.75 | Dr. Scramble's Shop, applied to an egg, 10% chance |
| Golden | ×2.5 | Hatch roll, weight 4 in 100 |
| Spirit Bloom | ×2.5 (one fan site says ×3) | Sakura Incubator |
| Bloom | ×1.25 | Probably the Sakura event |
| Silver | ×1.2 | Hatch roll, weight 6 in 100 |
With a single mutation there is nothing to argue about: a Golden pet earns 2.5 times a plain one of the same weight. The question is what happens with two or more.
The wiki contradicts itself here. Its calculator and its Pets and Eggs page (edited 2026-10-04) add the bonuses; its Mutations page says they multiply. Adding is the default in all our calculators because the calculator data is the more recently maintained source. Either way, the mutation multiplier then multiplies the size multiplier from weight and any boosts such as the x2 Money gamepass.
Worked examples
Why a pet can't be Golden and Rainbow
Silver, Golden and Rainbow all come from the same roll when an egg hatches (roll weights 6, 4 and 1 out of 100, so about 11 in 100 hatches get one of them). One roll gives at most one of the three. The others come from separate sources such as the Parasite Egg, a Mutation Consumable or the Sakura Incubator, which is how a pet can end up Golden and Bloom at once. The calculator lets you pick one of the three hatch colours plus any of the others.
A Golden + Bloom Kitsune at base weight
Kitsune base income is $1.8B/s at its base weight of 260 kg, so the size multiplier is 1.
- Adding: 1 + 1.5 + 0.25 = ×2.75, so income = $4.95B/s.
- Multiplying: 2.5 × 1.25 = ×3.13, so income = $5.63B/s.
The gap is about 14%. With two big multipliers the gap is much wider: Rainbow + Parasite is ×5.5 if they add and ×10.5 if they multiply. A heavy Rainbow + Parasite Kitsune at 2,080 kg earns $35.69B/s by the add rule and $68.13B/s by the multiply rule.
Settling it with one pet card
If you own a pet with two mutations, put its name, weight and mutations into the calculator above and compare both answers with the $/s on its card. Whichever matches tells you which rule the game uses. If the add rule is wrong, please email us; it changes every multi-mutation result on the site.
Common mistakes
- Stacking two hatch colours. Silver, Golden and Rainbow come from one hatch roll, so a pet has only one of them. The calculator won't let you pick two.
- Multiplying the mutation bonus onto the wrong number. Mutations multiply the weight-adjusted income, not the base income. A heavy Golden pet gets both bonuses.
- Assuming the multiply rule. It gives much bigger numbers for multi-mutation pets. Until someone checks a pet card, treat the add rule as the safer estimate.
- Using old multipliers. Updates can change values. Every multiplier can be edited in the settings of the pen calculator.
Questions
What is the best mutation in Steal An Egg?
By the wiki's numbers, Rainbow is the strongest colour at ×3.5 and Parasite the strongest other mutation at ×3. A Rainbow + Parasite pet earns ×5.5 its plain income if mutations add, or ×10.5 if they multiply.
Do mutations stack in Steal An Egg?
Yes, a colour can combine with other mutations. Whether the bonuses add or multiply is disputed: the wiki calculator adds them, the wiki's Mutations page says they multiply. This calculator shows both.
How much does Golden add to a pet's income?
Golden multiplies income by 2.5, so a Golden pet earns 2.5 times a plain pet of the same weight.
Can a pet be Golden and Rainbow?
No. Silver, Golden and Rainbow come from the same hatch roll (weights 6, 4 and 1 in 100 on the wiki), so a pet gets at most one of them. Other mutations, like Bloom or Parasite, come from other sources and can be added on top.
More Steal An Egg calculators
- Pen income calculatorYour whole pen: income, time to afford, fuse check, compare.
- Weight calculatorWhat your pet's kg does to its income, and the weight for a target.
- Fuse calculatorHow heavy a fused pet must hatch to beat the three you give up.
- Treadmill calculatorTime to afford every treadmill and trail.
To total your whole pen with mutations, use the Steal An Egg pen calculator.