The Legend of Zelda-Digdogger

Digdoggers are large spherical arachnids adapted to a subterranean lifestyle. They have leathery hides stretched over a rudimentary endoskeleton, and short, powerful limbs oriented for digging.

The Digdogger has been found to tolerate higher levels of carbond dioxide than other creatures, because their blood cells have a special and unique hemoglobin protein. Digdogger are able to reuse the oxygen inhaled when above ground, and as a result are able to surivie in low-oxygen environments such as underground burrows.

A Digdogger's diet primarily consists of small invertebrates found in the soil, and a variety of other subterran morsels. The Digdogger runs are in reality a kind of trap: the Digdogger senses when a victim falls into the tunnel and quickly runs along to kill and eat it. Because their saliva contains a toxin that can paralyze their victims, Digdogger are able to store their still-living prey for later consumption.