Steal an Egg · Pet
Koi
Koi is a Cosmic pet in Steal an Egg that earns a base $12M/s. It hatches from the Koi Egg, stolen from the nests of the Cherry Blossom biome.
EggKoi EggPet stats
Base income
$12M/s
Base weight
120 kg
Egg
Koi Egg
Grow time
25m
Speed reward
+4.2M
Cash reward
$1.2B
Source
Cherry Blossom
Biome nest
Rarity
Cosmic
Where to get Koi
Steal the Koi Egg from the nests of the Cherry Blossom biome, carry it back to your pen and let it hatch.
- Speed required
- 2.5B
- Guardian
- Oni Tiger
The guardian sleeps next to the nest; the faster you are, the easier it is to outrun it. Bigger eggs are worth more but slow you down. Eggs & guardians
Estimate based on the wiki formula
Koi income with mutations and size
| Mutation | 1× weight120 kg | 10× weight1,200 kg | 100× weight12,000 kg | 200× weight24,000 kg |
|---|---|---|---|---|
| No mutation×1 | $12M/s | $49.6M/s | $205M/s | $284M/s |
| Rainbow×3.5 | $42M/s | $174M/s | $719M/s | $995M/s |
| Parasite×3 | $36M/s | $149M/s | $616M/s | $853M/s |
| Fractured×2.75 | $33M/s | $137M/s | $565M/s | $782M/s |
| Scrambled×2.75 | $33M/s | $137M/s | $565M/s | $782M/s |
| Golden×2.5 | $30M/s | $124M/s | $513M/s | $711M/s |
| Spirit Bloom×2.5 | $30M/s | $124M/s | $513M/s | $711M/s |
| Bloom×1.25 | $15M/s | $62.1M/s | $257M/s | $355M/s |
| Silver×1.2 | $14.4M/s | $59.6M/s | $246M/s | $341M/s |
Estimate based on the wiki formula (marked beta there): income = base × (weight ÷ base weight)^(37/60) × mutation, with diminishing returns above 125× the base weight. In-game values can differ. See mutations and the income calculator.
How Koi compares
Neighbors by income in Cherry Blossom (5 of 8):
Other Cosmic pets
Koi guide
The Koi is the strongest pet in Cherry Blossom whose egg still grows in minutes. At 25 minutes it is the longest of those timers, and it pays off with $12M/s; the next step up, the Stag, needs 3 hours.
Koi Egg facts
- Biome: Cherry Blossom, 10th in the biome order
- Speed to enter: 2.5B
- Guardian: Oni Tiger
- Grow time: 25 minutes
- Hatch reward: +4.2m Speed and $1.2b
- Base weight: 120 kg
A good fit for medium sessions
Twenty-five minutes sits between the zone's quick eggs and its multi-hour ones. If you play in sessions of an hour or so, two Koi cycles fit comfortably, whereas a Stag Egg would not finish. The $1.2b reward is also the first payout in this zone that goes past a billion, enough for the Red Trail (750M, 4×) with money left over.
Compared with the Snowy Owl, the zone's other Cosmic pet ($7.5M/s, 15 minutes), the Koi earns 60% more for ten extra minutes and gives +500k more Speed per egg.
Rankings
It is 5th of 8 in Cherry Blossom, 19th of 28 Cosmic-rarity pets, and 104th of 198 overall, counting from the lowest earner.
Estimates with mutations and weight
From the wiki's documented formula (its calculator is labelled beta):
- Golden: about $30M/s
- Rainbow: about $42M/s
- 10× base weight: about $49.6M/s
- 100× base weight: about $205M/s
- 200× base weight: about $284M/s
- Rainbow with 100× weight: about $719M/s
Hard-tier sacrifice and Laboratory demand
The Shattered Rift sacrifice lists the Koi in its Hard tier, so it is one of the more demanding pets that banner can ask for. The Laboratory also asks for it as one of the Cosmic pets of the Cherry Blossom egg on the Biohazard, Experimental and Unstable DNA banners.
Data sourced from the Steal an Egg Wiki (CC BY-SA) and processed automatically; last synced 2026-10-11.