Angus was sitting on the cat condo next to my computer and a few minutes later he began coughing.
I briefly had a cat who had lung cancer, so a coughing cat is scary to me.
I shut the door because if he was going to puke, I wanted him to stay where there was a hardwood floor, and I went over to see what was going on.
The ball of yarn was hanging out of his mouth. I picked it up and began pulling gently. About 3 yards of yarn came out of his mouth. He stopped coughing. A few minutes later he was rolling on his back begging to play.
This is a cat who won't eat a single table scrap or cat treat. Yarn and carpet fluff, on the other hand - Yum!
Safety note: If I didn't know that he had just started eating the yarn I wouldn't have pulled it out, because it could have gotten tangled up in his digestive system and caused damage when removed. Or at least I've seen that scenario on Emergency Vets.