From rainbow-hued peacock spiders to spotted cheetahs, the wonders of evolution have produced some incredibly beautiful animals.

Most would say the naked mole rat—hairless, buck-toothed, and squinty-eyed—is not one of them.

Looks aside, the wrinkly African rodent is impressive for other reasons, including its resistance to cancer and inability to feel pain. (Learn why we find ugly animals cute.)

Now a new study finds that the mammal, which lives in highly populated underground burrows, can tolerate hours of very low oxygen levels and survive up to 18 minutes of anoxia, or total oxygen deprivation.

The research shows naked mole rats have a highly unusual mechanism that allows them to stop aerobic respiration and start metabolizing fructose, a sugar