Like the Big Friendly Giant in Roald Dahl's children's book The BFG, Australia's largest stick insect (Ctenomorpha gargantua) is thin, shy, and elusive. And like its smaller relatives that frequent American backyards, the Aussie giant belongs to the order Phasmida, from the Greek word for "apparition." Its barklike exoskeleton helps gargantua avoid capture by hungry predators and eager entomologists. It only comes out at night, and even then keeps to the highest canopies of Queensland rainforests. No one knows what it eats there, but in captivity it subsists on a diet of brittle gum and lilly pilly.

Despite the insect's best evasive efforts, in 2014 researchers at Melbourne's Museum Victoria happened upon a female specimen hanging on to a low-lying bush (she likely fell from the canopy above). The lucky scientists nicknamed the phasmid Lady Gaga-ntuan. She was only the third female gargantua ever spotted in the wild.

Now one of Ms. Gaga's female offspring, raised at the Museum Victoria, has the potential to become the world's longest stick insect. (Her rival is a 22.3-inch-long Phobaeticus chani, a species from Borneo.) Currently, Gaga fils is about a 10th of an inch short of the record.

Because so little is known about Ctenomorpha gargantua, experts aren't sure if the species is rare or just hard to find. Maik Fiedel, Museum Victoria's live exhibits coordinator, thinks that low reproductive rates among Lady Gaga's captive offspring might explain why so few gargantua are found in the wild.