These Alien masks

Anyone know - maybe someone into cosplay, where to find this kind of mask or maybe this mask, in Taipei are around Taipei?

Don’t think that’s necessary to get your Alien Residency Certificate.

sound of tumbleweed tumbling

Search out one of the film making groups on Facebook and ask there. I’d guess they’d have leads or ideas to things like that.

I would, as always, suggest you venture into the depths of Ximending where nothing is ever weird. Right behind one of the MRT exits is a street full of shops selling and renting these kinds of stuff.

Probably a party costume store would have one. There is one on Nanyang Street.