What does this simple rebus mean?

He digs out tiny caves and stores gold and silver in them. He also built bridges of silver and made crowns of gold. They are the smallest you could imagine. Sooner or later everybody needs his help, yet many people are afraid to let him help them. Who is he?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

All of Jacob's shoes are red except two.
All of Jacob's shoes are green except two.
All of Jacob's shoes are yellow except two.

How many shoes does Jacob have?

A thief is convicted in Mexico. He gets the death penalty. The judge allows him to say the last sentence to determine how the penalty will be carried out. If the thief lies, he will be hanged, if he speaks the truth he will be beheaded. The thief tells the last sentence and to everybody's surprise some minutes later he is set free because the judge cannot determine his penalty. What did the thief say?

Cristina was born in 1888. She just had her 30th birthday today how did that happen?

Can you solve the tricky chess rebus puzzle below by ciphering the hidden meaning?

Can you make the number 24 by utilizing the numbers 1, 3, 4 and 6? You must use one number only one time and you can use mathematical operation symbols anytime anywhere.

What has many teeth, but cannot bite?