Breeding the Rex produces fertilized eggs that require careful temperature control. Incubation temperature must stay between 32°C and 34°C - use Air Conditioners, Standing Torches, or Dimetrodons to maintain the range. At the correct temperature, the egg hatches in approximately 4 hours and 59 minutes.

After hatching or birth, the baby Rex matures over an extremely long period, one of the longest in the game, reaching adulthood in about 3 days and 20 hours at 1x maturation. The most labor-intensive part is the baby phase (0–10% maturation) when it can't use a Feeding Trough yet.

Offspring inherit parental stats and have a small chance to mutate, gaining +2 levels in a random stat. Use the breeding calculator to plan food requirements, incubation timers, and maturation phases.

The Rex's growth progresses through three stages: Baby (0–10%) lasts ~556 min and requires constant hand-feeding. Juvenile (10–50%) spans ~37h - it can eat from a Trough now. Adolescent (50–100%) takes ~46h - continues eating from troughs, nearly fully grown.

Imprinting during maturation provides permanent stat bonuses. At 100% imprint, the Rex gains 30% bonus damage and resistance when ridden by the imprinter. Keep various kibble types on hand, as imprint requests are randomized between cuddles, walks, and kibble feeding.

Planning a mass raise? The Rex raising calculator breaks down food needs per phase so nothing goes to waste. The Baby phase (0–10%) takes ~556 minutes and is the most hands-on, requiring direct feeding or a Maewing.

Raising multiple Rex simultaneously? Set the dino count and the calculator scales food requirements automatically. Match your food choice to your play schedule - longer spoil timers mean less babysitting.