Following Karl Sims seminal works, many approaches from the literature aims at generating artificial creatures using body-brain co-evolution. However, in simulation, creatures are not very realistic, they cannot be tested in physical robots. In this paper, we propose a system that can generate realistic walking artificial creatures. We co-evolve the morphology and the controller of virtual modular robots using GA. The morphology is generated by Graphtals while the global behavior of a creature is done by the cooperation of robot's modules moves. Each module has its own local controller, here based on an ANN. We integrate our system in Gazebo, a popular realistic robotic simulator. Experimental results show the capacity of our approach to generate realistic morphologies and behaviors with simulator parameters set up with realistic values. We expect the virtual robots generated with our system and trained in a realistic robotic simulator to better bridge the gap to reality.