1.
wild boar
A wild pig with coarse hair and tusks. Wild boars are common in Japan's mountains and are also one of the twelve zodiac animals.
猪 refers to wild boars.
Common expressions:
Counter: 頭
Zodiac:
猪/亥 is the 12th and last animal in the Japanese/Chinese zodiac. In China, the zodiac animal is a pig (豚), but in Japan it's specifically a wild boar.
Cultural note:
Wild boars have become a nuisance in rural Japan, damaging crops and occasionally entering urban areas. 猪突猛進 describes someone who charges forward without thinking, like a boar.