It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

One night, a man runs away from home. He turns left and keeps running. After some time he turns left again and keeps running. Later, he turns left one more time and runs back home—but when he gets home, he finds a man in a mask. Who was the man in the mask?

No one wants to have it, but if one got it, he does not want to lose it. What is It?

Which of the below owl is odd one out?

If we tie a Sheep to one peg, a circled grass is been eaten by the Sheep. If we tie the Sheep to two pegs with a circle on its neck, then an eclipse is eaten out of the grass by the Sheep. If we want an eclipse then we put two pegs and then put a rope in between them and the other end of the rope is tied up on the Sheep's neck.

How should we tie the peg and the Sheep so that a square is eaten out from the garden grass? We only have one Sheep rope and the peg and the rings.

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

I don't get anymore wetter, no matter how much rain falls on me.