The Sleestak are a reptilian bipedal humanoid species. They have a thin but wide-set mouths and large, round black eyes that are averse to light. Covered mostly in green scales, their bellies are yellow. Sleestak also have claws on their feet and on their hands, with a horn protruding from the top of their heads. They breathe with a pronounced hissing sound as if breathing through congestion. This is probably due to their wide set mouth and flat nostrils.
At one time, in the distant past, the Sleestak were known as Altrusians. They were a very peaceful and intelligent race and eventually grew into an advanced civilization, mastering many (if not all) of the secrets of the Land of the Lost. They created cities and temples. Unfortunately, the Altrusians lost control over their emotions, and destroyed their civilization becoming known as the Sleestak.
The Sleestak now are a degenerate race that have lost much of their knowledge and culture. They have come out of the Era of Intelligence and into the Era of Solitude. The Era of Intelligence was the period in time when the Sleestak first arrived at The Land of the Lost. The Sleestak also built these temples that are now called Pylons. There was a period when there was only darkness, before the Sleestak built the Time Pylon, which controls the light and dark cycles of The Land of The Lost.
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. The Sleestak eventually became ruled by a Sleestak called Sol. Sol reorganized the Sleestak and taught them how to hunt and kill.
The Sleestak are accomplished in the arts of building, foraging, and hunting, and make and use crossbows and nets to hunt. The crossbows are no larger than the size of a Sleestak's forearm. The nets are made to catch either the Altrusian Pig, or the Altrusian Moth which comes from the Altrusian Mountains. Also, during the Era of Intelligence, the Sleestak built Pylons and a temple that the Marshalls called The Lost City. They are fearless hunters, intimidated only by Kona, the beast of the north.
Due to their sensitivity at light, the Sleestak tend to live underground in the caves and caverns under The Lost City and the Land of the Lost. The thermal energies of the volcanic magma underground tends to control their periods of activity.
It is not known how many Sleestak live in the Land of the Lost. Although it might be as great as it once was, it's numbers might be no more than the 100-300 range.
Originally the free willed sentient species of the Land of the Lost under the leadership of The Zarn, they were enslaved by the Tachyon-manipulating Enik after he killed the Zarn and was sealed within the Central Pylon. Unlike their 70's counterparts, they possess razor-sharp teeth.
- For budgetary reasons, there were only three Sleestak costumes created for the 1974-1976 series. Therefore, only three Sleestaks were ever seen on screen at any one time, even if a scene's script clearly implied the presence of more than that number. To imply larger numbers of Sleestak, scenes were edited with extra footage inserted to give the impression of larger numbers.
- The Sleestak first appeared in the second episode of the original series, "The Sleestak God".
- The Pakuni word for the Sleestak is "Sarisataka".
- In the 1991 series, Sleestaks are an anamorphic trio of dinosaurs who follow their leader, Shung. They are one of the many antagonists in the show. Shung is an especially evil tyrant, powered by his crystal--which only intensifies his evil and makes him especially corrupt.