noun
giant stag beetle; Dorcus hopei
Refers specifically to the species Dorcus hopei, a large stag beetle native to East Asia. Often kept as a pet in Japan.
夏になると、オオクワガタを探しに山へ行く。
In summer, I go to the mountains to look for giant stag beetles.
彼はオオクワガタの幼虫を飼育している。
He is raising giant stag beetle larvae.
From 大 (おお, 'large') + クワガタ (stag beetle). The name reflects its size compared to other stag beetles.