Parrotfish in Steal an Egg

Parrotfish (Rare rarity) belongs to the Abyss Ocean zone. Abyss Ocean is zone 7 of 12 on the wiki's Biomes list; the wiki lists its entry requirement as 2.5M speed, and the nests there are watched by the Moby. You get it by carrying the Parrotfish Egg back to your pen.

At $220/s base income, Parrotfish sits 8th out of 8 in its zone — El Maja tops the Abyss Ocean at $130M/s. The listed figure assumes no mutation and a normal weight.

With a colour mutation and no size bonus, the same Parrotfish would earn roughly: Silver ×1.2 ≈ $264/s, Golden ×2.5 ≈ $550/s, Rainbow ×3.5 ≈ $770/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 +72k Speed, $22k, and the egg takes 1m 15s 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.

A Rare is usually the first egg in a zone that is worth waiting out the 5-minute nest reset for.