Steal an Egg Prehistoric Biome Guide: Speed, Pets & Rewards

Overview

The Prehistoric biome is the eighth zone on the Steal an Egg map route and serves as a major mid-to-late game checkpoint. It requires a base movement speed of 18 million to successfully steal eggs, with official tracking listing the access range between 17,000,000 and 18,000,000. The zone features a dinosaur-themed environment guarded by a T-Rex, and its egg pool contains eight distinct pets ranging from Rare to Eternal rarity, including the zone's top earner, Mosasaurus.

Speed Requirements & Egg Weight Strategy

Meeting the 18M minimum speed is only the baseline for accessing the zone. Eldorado recommends adjusting your target speed based on egg weight to account for movement penalties during the chase. For a very light egg, roughly 17.5M speed is sufficient, while carrying a very heavy egg requires approximately 20.5M. Because Prehistoric is grouped with Snow, Volcano, and Abyss Ocean as a mid-game biome where the margin for error shrinks, players should test a lighter egg first to confirm escape viability before attempting heavier, higher-value eggs.

Prehistoric Pet Pool & Income Rates

The Prehistoric egg pool contains eight pets with income scaling dramatically across rarity tiers: - **Rare:** Dodo ($280/s) - **Legendary:** Pterodactyl ($22K/s) - **Mythic:** Ankylosaurus ($120K/s) - **Cosmic:** Triceratops ($1.2M/s), Bronto ($1.5M/s) - **Secret:** Tralaledon, T-Rex ($25M/s each) - **Eternal:** Mosasaurus ($180M/s)

Income data for Tralaledon varies across guides: Eurogamer lists it at $850K/s, while IGN reports $32M/s. The Secret and Eternal tiers sit far above the Cosmic-tier pets that cap earlier biome pools. An earlier September 2026 snapshot only documented Ankylosaurus and Bronto, temporarily labeling Bronto as the game's income ceiling before the full pool was confirmed.

Hatching Rewards & Index Progression

Hatching pets from the Prehistoric biome grants one-time index rewards that significantly boost speed and currency. Key milestone rewards include: - **Dodo:** +240K speed, $28K - **T-Rex:** +420K speed, $2.5B - **Mosasaurus:** +600K speed, $18B

The Mosasaurus reward represents the largest single payout in the zone. These index bonuses are designed to accelerate progression toward the next biome threshold.

Guardian Behavior & Run Strategy

The T-Rex serves as the Prehistoric guardian and also appears as a hatchable Secret-tier pet earning $25M/s. According to Eldorado, the T-Rex is the last guardian before the Cosmic biome and is notably difficult to pull away from once it begins chasing. Getting caught in this zone also carries a higher time penalty, as Prehistoric sits far from the starting base, resulting in a longer run back if the egg is dropped or the player is tagged.

Progression Context & Map Placement

Prehistoric acts as a major progression gate. The climb from the previous biome, Abyss Ocean (2.5M speed), to Prehistoric (18M speed) represents a 7.2x speed increase. This is the second-largest progression jump on the map, surpassed only by the leap from Prehistoric to Cosmic. Securing stable Mythic-tier income before attempting this zone is recommended, as the speed multiplier required to bridge the gap demands consistent resource generation.