This white tiger (with very slight gray stripes) was making a noise that kinda sounded like a housecat coughing up a hairball. Only about 100 decibels louder. It wasn't a growl. It wasn't a cough. It wasn't a howl. I guess it was kind of a groan, but almost a roar. And he carried on for about half an hour. You could hear him through the whole exhibit.