Steal An Egg IndexCosmic Skeleton Boss in Steal An Egg
Secret · wiki data synced Oct 24, 2026
Cosmic Skeleton Boss is a Secret pet that earns $45M/s at its base size of 1,000 kg. It hatches from eggs stolen in Cosmic, where about 1 in 202 eggs is a Cosmic Skeleton Boss egg (0.495856%).
It is #93 of 236 pets by base income, and #4 of 8 in Cosmic.
- Rarity
- Secret
- Base income
- $45M/s
- Base size
- 1,000 kg
- Zone
- Cosmic
- Speed needed
- 700M
- Egg
- Cosmic Skeleton Boss Egg
- Drop chance
- 0.5% (1 in 202)
- Grow time
- 2h 30m
- Reward
- +1.6m Speed, $4.5b
How to get Cosmic Skeleton Boss
Train until you have at least 700M Speed, then go to Cosmic, zone 9 of 14, guarded by the Dragon. Steal eggs there and bring them back to your base to hatch.
Each egg that spawns in Cosmic has a 0.495856% chance to be a Cosmic Skeleton Boss Egg. That means you need to see about 140 eggs for a 50% chance of at least one, and 464 eggs for 90%.
A Cosmic Skeleton Boss egg takes 2h 30m to hatch, and the wiki lists its reward as +1.6m Speed, $4.5b.
Cosmic Skeleton Boss value by size and mutation
Income grows with weight but slows down past 125× the base size. These are the wiki's formula at three sizes:
| Size | Normal | Golden ×2.5 | Rainbow ×3.5 |
|---|---|---|---|
| 1,000 kg (base) | $45M/s | $113M/s | $158M/s |
| 10,000 kg | $186M/s | $465M/s | $652M/s |
| 100,000 kg | $770M/s | $1.93B/s | $2.7B/s |
Work out your own Cosmic Skeleton Boss: open it in the income calculator. All multipliers are on the mutations page.
How Cosmic Skeleton Boss compares
By base income Cosmic Skeleton Boss is #93 of 236 overall and #31 of 41 Secret pets. Just above it: Cosmic Dragon ($60M/s); just below: Mecha Scorpio ($45M/s).
Other pets in Cosmic
| Pet | Rarity | Base $/s | Drop chance |
|---|---|---|---|
 Centapede | Epic | $1.5K/s | 39.9% |
 Cosmic Gecko | Legendary | $30K/s | 34.4% |
 Cosmic Gorilla | Mythic | $180K/s | 19.6% |
 La Vacca Saturno Saturnita | Cosmic | $2.2M/s | 4.55% |
 Cosmic Dragon | Secret | $60M/s | 0.74% (1 in 134) |
| Cosmic Skeleton Boss | Secret | $45M/s | 0.5% (1 in 202) |
 Eternal Lunar Dragon | Eternal | $250M/s | 0.31% (1 in 321) |
 Unicorn | Divine | $1B/s | 0.02% (1 in 4,310) |
Source: Cosmic Skeleton Boss on the Steal An Egg Wiki (CC BY-SA). First listed on the wiki Aug 31, 2026, during the Monsters Are Coming week. Synced Oct 24, 2026.