Games like The Monster Breeder
Games like The Monster Breeder include Kenshi, 鬼谷八荒 Tale of Immortal, Planet Coaster, Cities: Skylines, and Cities: Skylines II. We matched them by the tags players give The Monster Breeder on Steam (Turn-Based Tactics, Management, Creature Collector, Sandbox, and Turn-Based): closest matches first, and among equally close ones the better-known games.

Kenshi
Shared: Sandbox · Immersive Sim · Management

鬼谷八荒 Tale of Immortal
Shared: Management · Sandbox · Simulation

Planet Coaster
Shared: Management · Sandbox · Simulation

Cities: Skylines
Shared: Management · Sandbox · Simulation

Cities: Skylines II
Shared: Management · Sandbox · Simulation

Empire of Sin
Shared: Management · Turn-Based Tactics · Turn-Based

Blackthorn Arena
Shared: Turn-Based Tactics · Management · Simulation

PC Building Simulator
Shared: Management · Sandbox · Immersive Sim

Totally Accurate Battle Simulator
Shared: Sandbox · Simulation · Realistic

Foundation
Shared: Management · Sandbox · Simulation

The Last Spell
Shared: Turn-Based Tactics · Turn-Based · Strategy

Crusader Kings III
Shared: Management · Simulation · Strategy

Automation - The Car Company Tycoon Game
Shared: Management · Sandbox · Simulation

Fell Seal: Arbiter's Mark
Shared: Turn-Based Tactics · Strategy · Turn-Based

Mount & Blade II: Bannerlord
Shared: Sandbox · Strategy · Medieval

Warhammer 40,000: Mechanicus
Shared: Turn-Based Tactics · Turn-Based · Strategy

Planet Zoo
Shared: Management · Sandbox · Simulation

Battle Brothers
Shared: Turn-Based Tactics · Strategy · Turn-Based

Graveyard Keeper
Shared: Management · Sandbox · Simulation

Gladiator Guild Manager
Shared: Management · Turn-Based Tactics · Strategy

911 Operator
Shared: Management · Simulation · Realistic

Football, Tactics & Glory
Shared: Turn-Based Tactics · Turn-Based · Management

RimWorld
Shared: Management · Sandbox · Strategy

Transport Fever 2
Shared: Management · Simulation · Sandbox