A Sleestak is a reptilian bipeds roughly the size and shape of humans. They have a lipless, wide-set mouth and large, round black eyes that are extremely sensitive to light. Their bodies are covered mostly in green scales but their bellies are yellow. Sleestak also have claws on their feet and on their hands, with a blunt horn protruding from the top of their heads. Despite having a normal sense of hearing they have no external ears.
When the Sleestak first arrived at The Land of The Lost they were a race of smart and inquisitive creatures. They built themselves a temples (now called Pylons). They even build the Time Pylon, which controls the light and dark. Then as the Sleestak went into The Lost City they became less intelligent as they had nothing to look at except hard rock and each other. This period is known as the Era of Solitude.Gradually they have become less intelligent and grew violent and absent-minded.The Sleestak eventually became ruled by a Sleestak called, Sol. Sol.
The Sleestak are accomplished the art of building, forging, and hunting. The Sleestak have made Crossbows and nets to hunt. The Crossbows are no larger that the size of a Sleestak's forearm. The nets are made to catch either the Altrusian Pig, or the Altrusian Moth which come from the Altrusian Mountains. Also during the Era of Intelligence, the Sleestak built Pylons and a temple that the Marshalls called The Lost city.