Tyrone Lavery has spent years on the lookout for a giant rat. Lavery, a mammalogist who works at Chicago's Field Museum, first heard of a tree-dwelling rat that locals on Vangunu Island called “vika” on his first trip to the islands as a postdoctoral researcher in 2010. Now, he's finally found it.

Tyrone reports the existence of a new (to science) species they've named Uromys vika in a study just published in the Journal of Mammalogy. It's the first new rodent found in the Solomon Islands in 80 years—"and it's not like people haven't been trying," as Lavery says in a press statement from The Field Museum. "It was just so hard to find."

The Solomon Islands, located just east of Papua New Guinea, are biologically isolated by the Pacific Ocean, and half the mammals native to the islands are found nowhere else. The unique nature of their ecosystem makes the Solomon Islands—much like the Galapagos—fertile ground for scientists.

Though researchers working in the Solomon Islands have suspected the existence of the vika for two decades, the rat found by Lavery and his colleagues John Vendi and Hikuna Judge is the first specimen recorded by scientists. They spotted it scurrying out of a felled tree, and judging by the shape of its skull, could tell that it wasn't like other species of rats native to the area. Before its discovery, Lavery had spent so long looking for the elusive rat that he was beginning to think that maybe the children's rhymes and folk songs referencing vika were just referring to regular black rats.

But his first instinct was correct. U. vika is more than four times the size of a regular rat, measuring about 18 inches long. It lives in trees, and its teeth are strong enough to crack into coconuts, chewing circular holes in the shells to reach the meat inside.

Lavery confirmed that the massive rat he found was a unique, new species by checking its DNA against the DNA of other regional rat species, and by confirming with Vangunu Island locals that the rat he captured was indeed the one they called vika. "Vika's ancestors probably rafted to the island on vegetation, and once they got there, they evolved into this wonderfully new species, nothing like what they came from on the mainland," the mammalogist explained.

The species will be designated as critically endangered, because commercial logging poses a huge threat to its rainforest habitat. It was hard enough to find just one of the rats, and there's no telling when (or if) scientists will see the vika again.