buffalo eye fungus or indonesian stalked puffball, Calostoma sp. of Borneo (Sarawak / Kalimantan)
The Iban-tribe called them Kulat Mata Babi (Boar-Eye-Mushroom) or in Bahasa Kulat Mata Pelanduk (Mouse-Deer-Eye-Mushroom) (another local names: kulat mata lembu, mata kerbau), is an edible fungus. It is also taken by some tribes as a drink that can lower the body temperature.