These are real Greater Short-Nosed fruitbat skulls (Cynopterus sphinx)! These bats are indigenous to the areas of Indonesia, Malaysia, and New Guinea.
They are sustainably hunted by the local peoples as a source of food and income. These bats have been studied and rated a level of "Least Concern" on the IUCN index of endangered/at-risk species due to their high reproductive rate and widespread distribution.
These skulls measure ~1.25" long and are available worldwide!