This paper presents an integrated design and fabrication strategy for fully soft, autonomous robots. The authors describe the development of an octobot, a robot composed entirely of soft materials, which is controlled by microfluidic logic and powered by monopropellant decomposition. The robot's body and microfluidic logic are fabricated using moulding and soft lithography, respectively, while the pneumatic actuator networks, fuel reservoirs, and catalytic reaction chambers are patterned within the body using a multi-material, embedded 3D printing technique. The fluidic and elastomeric architectures required for function span several orders of magnitude from the microscale to the macroscale. The authors demonstrate the untethered operation of the octobot, showcasing its ability to alternate between actuation states for four to eight minutes. This work lays the foundation for a new generation of completely soft, autonomous robots.This paper presents an integrated design and fabrication strategy for fully soft, autonomous robots. The authors describe the development of an octobot, a robot composed entirely of soft materials, which is controlled by microfluidic logic and powered by monopropellant decomposition. The robot's body and microfluidic logic are fabricated using moulding and soft lithography, respectively, while the pneumatic actuator networks, fuel reservoirs, and catalytic reaction chambers are patterned within the body using a multi-material, embedded 3D printing technique. The fluidic and elastomeric architectures required for function span several orders of magnitude from the microscale to the macroscale. The authors demonstrate the untethered operation of the octobot, showcasing its ability to alternate between actuation states for four to eight minutes. This work lays the foundation for a new generation of completely soft, autonomous robots.