counter
counter for large animals; head of livestock; counter for collected insects or certain headgear
Most commonly counts large animals such as cattle, horses, elephants, or large dogs. It is also used in specialist contexts for insects in a collection, and in limited traditional or cataloguing contexts for helmets, masks, and similar items; other counters may be more ordinary for those objects in everyday speech.
牧場で牛を三頭飼っている。
They keep three head of cattle on the farm.
動物園に新しいゾウが一頭来た。
A new elephant came to the zoo.
Twenty butterflies are arranged in this specimen box.