Steal an Egg · Pet
Royal Sphinx
Royal Sphinx is a Cosmic pet in Steal an Egg that earns a base $280K/s. It hatches from the Royal Sphinx Egg, stolen from the nests of the Desert biome.
EggRoyal Sphinx EggPet stats
Base income
$280K/s
Base weight
4,000 kg
Egg
Royal Sphinx Egg
Grow time
30m
Speed reward
+18K
Cash reward
$28M
Source
Desert
Biome nest
Rarity
Cosmic
Where to get Royal Sphinx
Steal the Royal Sphinx Egg from the nests of the Desert biome, carry it back to your pen and let it hatch.
- Speed required
- 10K
- Guardian
- Scorpion
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
Royal Sphinx income with mutations and size
| Mutation | 1× weight4,000 kg | 10× weight40,000 kg | 100× weight400,000 kg | 200× weight800,000 kg |
|---|---|---|---|---|
| No mutation×1 | $280K/s | $1.16M/s | $4.79M/s | $6.64M/s |
| Rainbow×3.5 | $980K/s | $4.05M/s | $16.8M/s | $23.2M/s |
| Parasite×3 | $840K/s | $3.47M/s | $14.4M/s | $19.9M/s |
| Fractured×2.75 | $770K/s | $3.19M/s | $13.2M/s | $18.2M/s |
| Scrambled×2.75 | $770K/s | $3.19M/s | $13.2M/s | $18.2M/s |
| Golden×2.5 | $700K/s | $2.9M/s | $12M/s | $16.6M/s |
| Spirit Bloom×2.5 | $700K/s | $2.9M/s | $12M/s | $16.6M/s |
| Bloom×1.25 | $350K/s | $1.45M/s | $5.99M/s | $8.29M/s |
| Silver×1.2 | $336K/s | $1.39M/s | $5.75M/s | $7.96M/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 Royal Sphinx compares
Neighbors by income in Desert (8 of 8):
Earns less
Scorpion
$18.5K/s(÷15 vs Royal Sphinx)
Other Cosmic pets
Royal Sphinx guide
Thirty minutes is the longest egg timer in the first three biomes, and it belongs to the Royal Sphinx. In exchange, the Desert's Cosmic pet earns $280K/s, ranking 26th of 28 Cosmics and 126th of 198 overall. Nothing else in the Desert comes close: the next pet down, the Scorpion, earns $18.5K/s.
The egg and its reward
- Grow time: 30 minutes
- Reward: +18k Speed and $28m
- Base weight: 4,000 kg
The wiki says nests reset every 5 minutes, so a Royal Sphinx egg holds a pen slot for about six reset cycles. Its +18k Speed is the largest hatch reward in the Desert, and combined with one Snake and one Sand Spider it reaches 41,400 Speed, past the 40K needed for Jungle.
Sphinx, Leviathan and King Mammoth
Comparing the early Cosmics helps decide whether the long wait is worth it:
- Leviathan (Lake): $220K/s, 25-minute egg
- Royal Sphinx (Desert): $280K/s, 30-minute egg
- King Mammoth (Snow): $400K/s, 15-minute egg
The Sphinx is about 27% stronger than the Leviathan for five extra minutes. Once you reach Snow, though, the King Mammoth earns more from an egg half as long, so the Sphinx is best valued as a top earner of your Desert and Jungle phase.
Mutation and size estimates
Using the wiki's formula:
- Golden: about $700K/s
- Rainbow: about $980K/s
- 10 times base weight: about $1.16M/s
- 100 times base weight: about $4.79M/s
- 200 times base weight: about $6.64M/s
- Rainbow at 100 times base weight: about $16.8M/s
A Golden Sphinx already beats a plain King Mammoth, so a mutated copy is worth keeping well beyond the Desert.
Data sourced from the Steal an Egg Wiki (CC BY-SA) and processed automatically; last synced 2026-10-11.