Zoology: Realistic Animal Overhaul

Overview

Zoology is a data-driven animal overhaul for RimWorld 1.6. It rebuilds animal stats from real zoological data, corrects ecological and physiological oddities, and adds configurable behavior systems for predation, reproduction, childcare, pets, combat and NPC animal companions.

Vanilla and official-DLC animals are recalculated from biological inputs such as body mass, growth and life-stage timing, gestation, litter/clutch size, bite force and claw/tooth dimensions. Where suitable data exist, values are taken from scientific literature and processed through an automated data pipeline, then mapped onto RimWorld's mechanics and balance.

Support development

If you enjoy Zoology and want to support its continued development, you can support me on Ko-fi or Patreon:

What’s changed

• Complete biological stat overhaul — species-specific changes affect far more than melee DPS: body size, movement, health and hunger-related values, reproduction, life stages, trainability, prey limits, ecosystem weight, Combat Power, meat/leather production, melee tools and more. Animals are generally stronger and faster than in vanilla where their real morphology warrants it, while encounter costs remain balanced.

• Ecology & distribution — biome distributions and ecosystem values have been revised to remove obvious zoological mismatches without breaking RimWorld's biome structure.

• Biological fixes — birds can flee by flying, ectotherms use cold-induced metabolic slowdown instead of ordinary mammalian hypothermia behavior, pregnancy raises food demand, selected cross-breeding relationships are corrected, guinea pig fur is removed, and many species-specific diet, reproduction and life-stage issues are fixed.

• Better animal audio — several species use more appropriate sounds. No more meowing cougars and tigers.

Configurable gameplay systems

Most gameplay-facing systems can be enabled or disabled independently in Mod Settings → Zoology Mod. Many also support per-species configuration.

• Advanced predation & pack hunting — Zoology replaces vanilla's strong bias toward the weakest available prey with a more species-specific prey-selection system based on body size, life stage, kinship and relative Combat Power. Some predators still prefer safer prey, while large mammalian predators can actively favor larger prey instead of always targeting the weakest and smallest animal. Pack hunters can coordinate attacks against prey too dangerous for a lone hunter. Snakes, frogs and other configured species swallow prey whole instead of chewing corpses.

• Smarter fleeing — prey flee active hunters, predators abandon hopeless chases, and animals can react to nearby non-hostile predators. An optional size-aware danger system also controls fleeing from colonists, mechanoids and other threats, with per-species exceptions.

• Predators defend their kills — predators can guard owned prey corpses against scavengers, colonists and mechanoids. Small, harmless scavengers can be ignored instead of triggering pointless attack.

• Wild reproduction & ecosystem regulation — wild animals actively seek compatible mates. Wild-to-wild reproduction can pause when the map's seasonally adjusted ecosystem capacity is overloaded, and excess wildlife can leave the map instead of multiplying without limit.

• Mammal lactation, childcare & egg incubation — mammalian young can nurse from mothers; childcare species keep offspring nearby and defend them; egg-laying parents can track, incubate and protect their own clutches. Nearby herd or pack members may join family defense.

• Pet recreation & expanded bonding — colonists can walk dogs, play fetch and play with suitable pets. Bonding can use vanilla rules, expanded pet bonding, or optional expanded bonding for all animals.

• Direct animal control / Beastmastery — eligible trained animals with an assigned master can be drafted and given movement/attack orders within their master's command range. The Zoology Beastmastery trainable is Odyssey-gated.

• Animals in NPC raids and human groups — suitable dogs and faction-specific animals can appear alongside raiders, traders and other human groups as companions of individual handlers. They follow and defend their handler, can switch to another suitable handler if needed, and retreat with the group. Animals only appear when someone in the group has enough Animals skill to handle them. Zoology adds conservative animal pools to suitable Outlander, Pirate, Tribal, Pigskin, Waster and Yttakin groups, with supported mod animals where available.

• Scavenging — configured scavengers can consume rotten and, where allowed, desiccated corpses at reduced nutritional value.

• Raiders ignore small pets — small non-threatening pets can be treated more like livestock unless they actively join combat or go manhunter.

• Bionics for animals — many vanilla bionic implants can be installed on compatible animals, with their effects adjusted to the animal’s body size. This allows you to augment animals without needing a separate animal-bionics mod, and works with Combat Extended.

• More optional behavior — slaughter aggression, wildlife wound licking, configurable roamers/trainability, ectotherm assignment, species-specific mammal/childcare/scavenger lists and other runtime animal features.

• Animal damage reduction — optionally reduces implausible damage from tiny animals or unarmed humans attacking much larger targets, while excluding genuine predator–prey interactions. This system is automatically disabled with Combat Extended because CE already handles this through its armor and penetration mechanics.

The settings menu contains additional advanced and per-species controls; see GitHub for the complete mechanic list and framework documentation.

Mod compatibility

Zoology is designed so invasive runtime systems can be disabled individually if another mod replaces the same behavior.

Dedicated integration is included for:

• Combat Extended

• Vanilla Expanded Framework and supported Vanilla Animals Expanded modules

• Alpha Animals

• Dinosauria

• Megafauna

Combat Extended receives dedicated animal combat patches based on biological inputs such as hide thickness/toughness, claw and tooth dimensions, and bite force. The optional life-stage penetration override prevents juveniles from inheriting implausibly high adult penetration.

Known incompatibility: Animals Are Fun Continued is currently marked incompatible.

Because Zoology changes many animal stats and patches several AI decisions at runtime, conflicts are still possible with other broad animal overhauls. Most behavioral systems can be disabled independently for compatibility testing.

Community & development

GitHub repository:

https://github.com/AbobaShark/ZoologyMod-Framework-For-Rimworld