How can we generate and visualize tera-scale graphs efficiently? Although there are several graph generators available, they lack scalability, and require additional time to upload graphs for further analysis in distributed systems. Visualizing a massive graph from a graph generator is another challenge since the amount of information in the graph exceeds the resolution of a typical screen. In this paper, we proposes TeGViz, a distributed Tera-scale graph generation and visualization tool. TeGViz consists of two modules: graph generation and visualization. The graph generation module TeG generates a wide range of graphs including Erd1/2os-Rényi random graph and realistic graphs including RMAT and Kronecker directly on distributed systems. Thanks to our carefully designed parallel algorithms, TeG outperforms competitors in terms of scalability. The visualization module Net-Ray summarizes graphs using spy plot, distribution plot, and correlation plot to find regularities and anomalies effectively and makes it easy to understand generated graphs.