King Mammoth in Steal an Egg

King Mammoth hatches from the King Mammoth Egg, a Cosmic-rarity egg found in the Snow. Snow is zone 5 of 12 on the wiki's Biomes list; the wiki lists its entry requirement as 170K speed, and the nests there are watched by the Yeti.

The wiki lists its base income as $400K/s, which ranks it 3rd of the 8 Snow pets by base rate — Ice Dragon tops the Snow at $65M/s. Base rate is what a normal-size, un-mutated hatch earns; everything above that comes from the size roll and the colour mutation.

With a colour mutation and no size bonus, the same King Mammoth would earn roughly: Silver ×1.2 ≈ $480K/s, Golden ×2.5 ≈ $1M/s, Rainbow ×3.5 ≈ $1.40M/s (multipliers from the wiki's Mutations page; arithmetic is ours). Add a Giant (×3) or Huge (×5) size roll on top and the numbers multiply again.

Hatching it pays a one-off reward of +22.4k Speed, $40m, and the egg takes 15m to grow in the pen. That reward is the reason low-income eggs are still worth stealing early: the speed bonus is what gets you into the next zone.

Cosmic-rarity pets sit near the top of their zone's table; expect the nest to be contested on busy servers.