These gorgeous beetles are a type of RHINOCEROS BEETLE which do not have a common name but have the scientific name Xylotrupes gideon siamensis, which is a bit of a mouthful!  They are one of the most common rhinoceros beetles across the tropical rainforests of southeast Asia, and these particular beetles originated in Thailand.  The male has impressive horns which is one of the main features of all the world's many species of rhinoceros beetles:

The female beetle does not have any horns at all, a typical feature of this beetle family.  She is on the right of the pictures below, alongside the male, so you can clearly see the difference between them:

Like all rhinoceros beetles this species feeds on fruit, and it seems that a favourite food is banana as you can see here!