However they evoluted, at no point in their evolution they invented cloth. Aliens
never do, no matter how sophisticated their society is ...
And finally, the awesome, but still naked Thargoid:
Seriously, though, I would love, if Thargoids would at least feature some other cultural expressions, suitable to creatures with exo-skeletons.
Metal inlays, in complicated and beautiful patterns, for example, representing their status in the hive.