Regal horned lizard

This lizard wears a ‘crown’ of thorny horns made up of four large horns at the back of its head and six smaller ones on the temples. Another distinguishing characteristic is the row of keeled scales on its abdomen.

When threatened, the lizard may try to divert its enemy’s attention with head-bobbing, push-ups, and nodding. If these fail, it rolls over, displaying its pale belly and splaying its short, white legs out stiffly. Some believe it’s only playing dead. Others think this action focuses a predator’s attention on the lizard’s spiky fringes — which look rather like sharp, serrated teeth — and advertises its unappetising spininess.

As a last resort, these reptiles will squirt a surprise spray of blood from their eyes. These lizards have evolved the ability to restrict blood flow from the head. The resultant pressure ruptures small blood vessels near their eyeballs and the ocular sinus, a pouch below the eye, swells as it fills with blood. A sudden surge of pressure then releases a spurt of blood that may leap 1 – 2 metres.

This bloodbath works best when delivered directly into the mouth, rather than the eyes or nose. That’s why the lizards aim for their enemy’s mouth, or wait till the last second, when their predator has its jaws around them, before squirting!

The lizards probably get the foul-tasting chemical in their blood from their diet of ants, especially venomous harvester ants. Snapping their sticky tongue out like a rubber band, they lap the insects up and catapult them to the back of their throat. There, the ants are coated in thick mucus, before they’re swallowed whole. Thus, the lizards are protected from the ants' stings, allowing them to exploit an oft-avoided food source.

They need a big stomach to hold lots of ants, which leads to their stocky build and lack of speed. Their diet could have been the driving force behind the evolution of their many bizarre defence mechanisms.