Lord Ganesha represents Om or the Pranava, which is the chief Mantra among the Hindus.

Nothing can be done without uttering it.
This explains the practice of invoking Ganesha before beginning any rite or undertaking any project.

His two feet represent the power of knowledge and the power of action.

The elephant head is significant in that it is the only figure in nature that has the form of the symbol for Om.

The significance of riding on a mouse is the complete conquest over egoism.

The holding of the ankusha represents His rulership of the world.

It is the emblem of divine Royalty.

Ganesha is the first God.

Riding on a mouse, one of nature’s smallest creatures and having the head of an elephant, the biggest of all animals, denotes that  anesha is the creator of all

Elephants are very wise animals; this indicates that Lord Ganesha is an embodiment of wisdom.

It also denotes the process of evolution—the mouse gradually evolves into an elephant and finally becomes a man.

This is why Ganesha has a human body, an elephant’s head and a mouse as His vehicle.

This is the symbolic philosophy of His form.

Swami Sivananda
 To be continued  ...