The Rhinoceros Beetle is a large insect that can reach lengths of almost 4.5 cm. The length of the 'horn' varies. Only males have the horn.
These beetles feed off the juice from coconut palm trees, particularly the juice from new shoots. Their larvae feed off compost and other rotting vegetation and are also found in horse manure.
The Rhinoceros Beetle is active at night and is often attracted by light which gives you your best chance of seeing one.
They occur over most of South Africa. They are an invasive species in many countries around the world and cause damage to plantations of coconut palms.
Although there are around 50 species in the genus Oryctes they do not all have horns.
References and further readingPocket Guide - Insects of South Africa - Author: Mike Picker & Charles Griffiths - Published: 2015 - Page: 73
Insects of Southern Africa - 1st edition - Author: Clarke H. Scholtz and Erik Holm - Published: 1989 - Page: 222
Field Guide to Insects of South Africa - Author: Mike Picker, Charles Griffiths and Alan Weaving - Published: 0 - Page: 208