8675309
When my cat was just a wee thing he ate around twelve feet of yarn. Wouldn't eat, had nasty diarrhea kept trying to barf but just dry heaved. When he finally was able to cough some of it back into his mouth I was able to pull the rest out--veeeeeeeery slowly. Nasty.
Tell your friend to get the cat to the vet or start digging a hole. Keep us posted.