In the isolated Solomon Islands, mothers and fathers have been known to sing to their children of apocryphal rats.
In one rhyme, Kamare and Isuku go scurrying up a child, one rat on each side. They climb the ribs and reach the armpits, where the singer finally tickles the child.
Isuku, as the song goes, is what your average New Yorker might consider a fairly normal-size rat.
But Kamare, the children are told, is big.
The mammalogist Tyrone Lavery learned of this rhyme as he searched the Solomons for another giant rat - Vika - rumored to live in the trees, a foot-and-a-half long, with teeth so sharp it can punch through a coconut.
And unlike the rats in the song, Vika is very real. Its scale-covered tail, great jaws and a few rare photos were revealed this week in the Journal of Mammalogy.
Uromys vika isthe first rodent species to be discovered in the islands in nearly a century, at the end of Lavery's long search.
He was first drawn to this chain of hundreds of islands in 2010, as he researched mammals at the University of Queensland. Far off the coast of Australia, the Solomons are renowned for elusive, unique species that evolve in near isolation from the rest of the planet - like the Guadalcanal monkey-faced bat.
The PhD student was sitting around a fire with village elders on the island of Vangunu, in the thick-forested caldera of an ancient volcano.
As rice and sweet potato cooked in the flames, Lavery recalled, he asked the elders what things he might find in the forests.
"They told me about this giant rat they called Vika," he said. They said Vika lived in the trees, was a bit smaller than a possum, and was so strong it could chew through thick-shelled ngali nuts.
Lavery knew giant rats exist in the Solomons - but of the few species to have been documented, some had not been seen since the 19th century. And no rodents had even been found around Vangunu, he said.
So he set off at once into the forest with the villagers and spent several days and nights searching among the palm trees.
He found hard nuts with great holes chewed into them, just as the elders had described.
One night, as he held a spotlight up to the thick canopy of trees, Lavery thought he saw two rats running along a branch.
"It was only a fleeting glimpse," he said. "To this day, I can't be certain whether it was Vika . . . But it was enough to start me thinking we had a chance to find this rat."
As he researched from the university in Australia, Lavery found that Vika was more than a local rumor. Its name was listed in a dictionary of words from the region that an anthropologist had compiled in the 1990s.
The definition of Vika: "A very big rat that eats coconuts."
When Lavery went back to the island in 2011, he found a large dropping in the rain forest. A lab analysis turned up ngali nuts and rodent hair in the stool.
And so Lavery went back into the rain forest again and again - nearly a dozen times in five years, he said.
Residents of the village of Zaira were happy to guide him, he said, because their forest was one of few parts of the island that had not yet been ravaged by logging, and they were fighting to protect it.
"They understand it's important to document," Lavery said.
But in all those trips - weeks at a time in dense palm forests under pouring rain - he never again found any evidence of Vika.
Meanwhile, loggers were toppling trees all over the island.
Lavery never doubted that the rat once existed, he said, but "I was concerned it might already be extinct."
And then one day in late 2015, back in Australia, he got a phone call from the island.
Loggers in a camp outside the village had felled a kapuchu tree - particularly prized for its wood.
After the tree hit the ground, something big and brown came scampering out of it. The loggers knew an Australian scientist had been searching for Vika for years, and word of the animal spread through the village.
Two friends of Lavery - John Vendi and Hikuna Judge - managed to catch the animal.
It looked like an adolescent, and it had lost part of its tail in the fall or subsequent capture. Still, it was estimated to be a foot-and-a-half long, and might grow to weigh more than two pounds - four times larger than your average garbage rat.
Young residents in the village had never seen anything like it, but the older men recognized it as the elusive Vika.
"This is absolutely amazing," Lavery said when he learned of the discovery, and at once set about arranging for the rat's transport to a lab.
But here, more trouble. The rat died of its injuries shortly after its capture. With nothing to preserve it, villagers buried it in a stone-lined tomb, where it rotted for 10 days before a friend of Lavery's dug it up and brought it to a museum in Queensland.
By then, not much was left of the specimen but bones and hair and a bit of tail. And yet, as Lavery and Judge wrote in their paper, bones and hair were proof enough.
They sketched its wide claws and deep teeth, and measured its hairs and the scales on its tail. They compared it to every rat known to have existed in the Solomon Islands - giant or otherwise.
It was not an Uromys rex, for those were known to be gray. Its remains didn't match Uromys porculus, or neobritannicus, or any other species.
It was, they concluded, a brand-new species - descendant of the first rodents that floated on natural rafts to the Solomon Islands, cousin to the long-lost emperor rat: Uromys vika, or the giant rat of Vangunu island.
"It's a bittersweet moment," said Lavery, who completed his studies and now works at the Field Museum in Chicago.
All those treks through the rain forest paid off, and yet he believes the Vika rat is rare, and in danger of extinction by the same loggers who accidentally found it.
Now that the rat's existence is proven, Lavery will seek to have it placed on an endangered species list.
In the meantime, he's searching another island in the Solomons for another rumored creature - called Kwete by local residents, or the monster rat of Malaita.