Arhats have many names: sometimes Luohan or Aluohan in Chinese, and Saints or Sages in English. Arhats are people who have attained enlightenment and renounced their false egos. At their level, all vexations have ended, the cycle of rebirth has broken, and so they enter Nirvana.
There was once a famous Arhat named Ajita, also known as “The Arhat Riding a Deer.” When Ajita decided to seek enlightenment, he left the employ of his king, and went to the mountains to become a monk. After reaching enlightenment, he rode back to the palace on a deer. He was immediately recognized by the guards, and brought before the king. When Ajita taught the king the Dharma, the king decided to renounce his throne to his son, and follow Ajita back to the mountains to become a monk himself. To show his gratitude and share his learning, the former king also returned to spread the Dharma message; enabling sufferers in his kingdom to also find liberation.