Wiktionary
viscacha rat
n. A South American rat-like rodent, (taxlink Octomys mimax species noshow=1).
Wikipedia
Viscacha rat
The viscacha rat (Octomys mimax), or mountain viscacha rat, is a species of rodent in the family Octodontidae. It is endemic to Chile and Argentina.
It is the only living species within the genus Octomys. This diploid genus (2n = 56) may be ancestral to the two unusual tetraploid species Tympanoctomys barrerae and Pipanacoctomys aureus.