Chilli crab is a Singaporean seafood dish. Mud crabs are commonly used and are stir-fried in a semi-thick, sweet and savoury tomato and chilli based sauce.

Chilli crab has been promoted by The Singapore Tourism Board as one of Singapore's National Dishes, and can be found in seafood restaurants all over the island.

 It is traditionally eaten with bare hands as a means to savour the juicy crab meat with its sweet and spicy chilli sauce. Restaurants often provide wet towels or a washing bowl with lime in order to cleanse your hands after the meal.

Its sauce is described as "sensuous" and "sweet, yet savoury", with a "fluffy texture".Mud crabs ( Scylla serrata ) are the most common type of crabs used for the dish, although other species of crab can be used too.

Chili crab is listed at number 35 on the World’s 50 most delicious foods, complied by CNN Go in 2011. This Singaporean iconic seafood dish is a must try to complete the culinary exploring journey of any travelers. 

According to wikipedia.