Dr. Hal "Otacon" Emmerich was the eccentric chief engineer of Metal Gear REX. After her rescue from the Imperial assault, he became the adoptive father of Sunny. A devoted fan of anime, Hal's chosen nickname was derived from the Japanese animation and culture convention Otakon, which he regularly attended. Otacon was a gifted scientist, possessing a high intellect in computer programming and mechanical engineering. A big fan of Japanese animation shows, especially that of the sci-fi and mecha genres, his hobby also gave him an optimistic inspiration and drive to help create new beneficial technologies and innovations for society with his genius, which was also reinforced with a sense of responsibility and level-headed perspective, especially during his experience of the Kalimdor Incident.