At first glance, it looks dead. Laid on its back, its legs up and stomach exposed, the spiny-tailed lizard, locally known as the dhub, is motionless as it lies sprawled on the highest point of the rocky structure that houses its burrow.
Even the zookeeper is not sure of the animal's well-being. She approaches quietly, until suddenly the reptile opens its eyes. Seconds later it wriggles, tumbles onto its front and bolts back into its den.
"It was sunbathing," explains Dr Marisol Dingal, the reptile house keeper at Al Ain Wildlife Park and Resort. "It actually looked annoyed at us for interrupting."
Although some may rate Dr Dingal's scaly charges as among the zoo's "less cuddly" creatures, she says they are actually "very cute" when you get to know them.
"They have unique characteristic like every other animal, it is just more hidden and unknown as most people don't interact much with reptiles," she said.
The timid grey dhub loves to bask in the early morning sun before hiding away in its burrow. In late afternoon it ventures back out, catching the last rays of light before the sun sets.
It is also known as the Samakat al Sahra ("fish of the desert") or the dragon or "little dinosaur" of the desert. That is echoed by Dr Dingal, who refers to the zoo's eleven dhubs as her "little dinosaurs".
How big they get depends on how much food they find. Although the juvenile lizards eat insects, by adulthood - when they can be more than 65 centimetres long - they are fully herbivorous, favouring coarse desert grasses and evergreen herbs.
Their slow metabolism lets them survive for weeks at a time without food. Nor do they need to drink much, as they extract most of their water from their food. Excess salt is excreted through a gland near the eyes.
They are found throughout the UAE, living on gravel terrain and in burrows in sand dunes. They usually live in loose colonies, in separate burrows, some 20-50 metres apart.
What is known as the dhub is actually two species - the Egyptian spiny-tailed lizard (Uromastyx aegyptius microlepis) and Leptien's spiny-tailed lizard (Uromastyx leptieni), both of which are found in the UAE. They are very similar; indeed, the Leptien's lizard was only recognised as a distinct species in 2000.
"It is a bit hard to tell them apart," Dr Dingal admits. The biggest difference is that the Leptiens are dark grey when young, while the Egyptian variant is a lighter shade of grey-brown, with stripes and spots on its back. The adults of the two species are more similar in colour, although the Leptien's has bigger, coarser scales.
They change colour with the temperature, from a dark, rocky grey when cool to almost white and yellow after a period basking in the sun.
And despite its formidable appearance, the dhub tends to avoid conflict, preferring to flee than enter a fight.
"Only if they are stressed out or cornered do you see their fighting instinct. They don't like strangers and so if they are around one, you may see them swing that muscular spiked tail and hiss, exposing their teeth in a show of strength."
Even though they see their keeper every day, the dhubs keep their distance.
"They don't let you pet them, they are shy and hide away. But you can see them peeking at you from their hiding spots, keeping a close eye on what is happening in their environment," Dr Dingal says.
Their reticence may be wise.
"It tastes like chicken," said Rashid Mohammed, an Emirati in his 40s who has barbecued the lizards many times during outings in the desert and near the Hajar mountains of Ras Al Khaimah.
"Now it is not allowed to eat them, which is too bad, because they are tasty and are a very well-known delicacy among the Gulf nationals."
Their meat is full of nutrients, he says, and the fat can be boiled and used as a liniment. It is also said to cure impotence.
"The dhub is one of the favourite lizards of visitors [to the zoo] - mainly because of it being known as a delicacy," Dr Dingal says.
But hunting them was banned by a 1983 federal law, and trade is banned under the Convention on International Trade in Endangered Species of Flora and Fauna. Still, the UAE's population remains under threat from the destruction of their habitat by development.
"They would never hurt anyone," said Dr Dingal, adding "that is one of the things we teach at the zoo. That even the less fluffy of the animal kingdom has an important role in the ecosystem and should be protected."