Good Riddles

Question: What has ears, like a cat and a tail like a cat, but is not a cat?

Question: What goes 99 thump, 99 thump, 99 thump?

Question: What is the tallest building in the world?

Question: What arrives at the end and can occur several times a day, once every month, or last millions of years?

Question: What disappears as soon as you say it?