Dutch word voshaai comes from Dutch vos, Dutch haai (Greedy person. Shark.)

Detailed word origin of voshaai

Dictionary entry	Language	Definition
vos	Dutch (nld)	A crafty, ingenious person. Fox. Fox fur. Horse with red or red-brown fur. Red fox specifically.
haai	Dutch (nld)	Greedy person. Shark.
voshaai	Dutch (nld)	Any shark of the family Alopiidae. Common thresher, Alopias vulpinus.