Mumak handler

Most likely there is a specific culture or just one single tribe in Far Harad that supplies the Haradrim confederacy with oliphaunts, for both warfare and labour. Even though I imagine that the kingdom of Near Harad looks down on the southern tribes as savages, they do see the value in the Mumak suppliers and handlers and have a grudging respect for these people.

Like the real-life mahouts of India the Mumak handler is wielding an ankusa, which is used to poke and stab the poor oliphaunt in sensitive spots on its head. This way the animal is angry enough to not mind running straight into enemy troops.