This is 'Mu Yong', literally frizzy pork, also known as pork hair, or pork fibers. You may have seen it in the snacks section of Asian grocers and wondered whether it's food or for scrubbing plates clean!
It's made from oven dried pork, the pork is rubbed into fibres or hairs. It has a very savoury taste, similar in taste to barbecue flavour crisps/chips, but without the artificial flavourings. It's often eaten just as a snack, but it's also used to add a savoury flavour to some Thai dishes.