The 18 Lohan (十八 罗汉 Shí bā Luóhàn).
A Lohan (Arhat, Arahat or Arahant) comes from Theraveada Buddhism, and is one who has followed the Eightfold Path and therefore is free from earthly existence. A Lohan is no longer subject to the wheel of reincarnation, no more births, or rebirths, he is karmic free. Asavas (physical cravings for sensual pleasures) are gone.
Lohan are known for their supernatural power, great wisdom and courage and are able to ward off evil. Hence, they have become Buddhist guardian angels standing guard at many Buddhist temples. These are the 18 Lohan in no particular order.