Eupatorus gracillicornis can be found in many Asian countries.

They feed on tree sap in the wild. It has been raised in Thailand for many years for insect enthusiast, and is also a natural protein source for many villagers and rural people.

It flies at the end of the raining season, where it can be quite common.

There are minor males with very small horns, and XXL males with extended appendices.

It can be observed at night in September and October.