In this paper, an artificial creature is designed to have its own genome in which a specific personality is encoded. The genome is composed of 14 chromosomes each of which consists of three kinds of genes such as fundamental genes, internal-state-related genes, and behavior-related genes. To represent various types of personality, a large number of genes are needed. In this case, if gene values are assigned manually for the individual genome, it becomes increasingly difficult and time-consuming to generate a desired personality reliably and consistently. Considering this problem, this paper proposes an evolutionary process that generates a genome encoding a specific personality of an artificial creature. The process evolves a population of genomes such that it customizes the genome, which meets a simplified set of personality traits desired by the user. The evaluation procedure for each genome of the population is carried out in a virtual environment using a tailored perception scenario and a dedicated fitness function. An artificial creature, Rity, is developed in the virtual 3-D world created in a PC to demonstrate the effectiveness of the proposed process.