A light weight flashlight
Packing a small flashlight is always a good idea. Sometimes you have to walk in the dark andbeing able to see where you are going in the bush is always a good thing!

Medical kit
Pack a small bag or medical kit with some pain killers, any chronic medications (enough for the trip), some insect repellent, any vitamins etc. The park will have basic medical aid kits; just pack the things that you might not be able to get in South Africa.
 

Anti-malarial
The Kruger National Park is in a malarial area. Please do not forget your prophylaxis

A good book
Consider packing a book that you will enjoy reading. There will be some leisure time during the middle of the day

What to wear

Layers of clothing (from cool to warm)

T-shirts, Trousers, windbreaker, fleece, sweaters for early morning and late afternoon game drives

Muted colored, lightweight clothing is best for game viewing.

Game drives are generally conducted in the early morning and the late afternoon, which can be a bit chilly.

Comfortable walking shoes or sneakers

Warm scarf or pashmina

Sun glasses

Sun hat