Mecha Crawler in Steal an Egg

Mecha Crawler is listed by the wiki as an Event pet (Monster rarity). Event pets do not spawn in normal zone nests; according to the Eggs page they are only obtainable through the Store or special events such as Admin Abuse, so if you are looking for one in a biome you are wasting speed.

At $320M/s base income, Mecha Crawler sits 11th out of 33 in its zone — Mecha Scrambler tops the Event group at $7.5B/s. The listed figure assumes no mutation and a normal weight.

With a colour mutation and no size bonus, the same Mecha Crawler would earn roughly: Silver ×1.2 ≈ $384M/s, Golden ×2.5 ≈ $800M/s, Rainbow ×3.5 ≈ $1.12B/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.

Neither a hatch reward nor a grow time is recorded on the wiki for Mecha Crawler yet; if you have hatched one, the timer on the pen and the reward pop-up are the two numbers worth noting.

Monster-rarity pets are the Rift's own tier; they are not found in zone nests.