Could a skinwalker kill a alien and pose as it?

Predator Vs Alien. Nice.

O̷̼͓̤̣͕͍̠͍͝ͅͅM̵̶̛̙̟̫͇̪̖̯͕̩̝E͏̡̢̤͈̩͍̯̗͕͎͎̥̫̘̙͖͇̤̻͢͜ò̦̳͈̰̩̣̙͇̖̭̪̲͖̤͡͝ͅͅͅn̷͉̼̱͉͎̜̰͜_Ȩ̷̝̦͕̮̫͇͖̪̪̀͟͝ͅ ̶̱̳̼̝͖̹̹̻̣̺͓̜͜͞͡Ś̴̢̛̥̪̭̳̥̞̩̞̙̼͍̟̗̻̮͟A̵̛̮̪̗͎̺̼̯̠̘͉̼͠ͅi҉̩͔͖̳̰͕͉͕͓̘͚͙͔̰̦͔̜͘͝ͅd̥͔͖̥̠͎̻͍̣̯̞̗͇͜͜ ̕͞͏̰͕̠a̴̭̟̠̞̳͇̙͕̻̫̘̭͈̲̹̕͠ņ͉̣̻̩͜_ṇ̵̢̼̺͎͟ͅó̡҉̼̫̳͙̰͔ͅÝ̶̲̞͇̪͈̥̮̫̹͕͡Į̶̛͖͕͔̩͖̼_N̷̜̩̜̤̲̬̞̯͘͜G̟͍͔̹̣͈͢͡?̡̹̹̟͖̕͟͜͠

>>17917989
It depends on how the skinwalker (fleshgait? not sure what it's called now, been away for a bit) is assuming the subjects appearance...if it's simply taking it's skin and making it into pseduo-costume then I don't see a reason it couldn't. If it's just sucking in it's DNA or w/e and finding out how to replicate it's appearance then probably not. I'd assume aliens have different DNA or none at all (replaced with something else).

>>17917989
Greys likely have tech to detect it but could be snuck up on.