Balls in the mouths of Dragons and thos Guardian Dogs.

What is the signifgance of the ball inside the mouths of dragons and those dogs near Budhist temples and in Asian art? Is it magical? Powerful? Do they die if they drop it? Is this the spheres referred to in Dragon Ball Z? (Never seen the cartoon, only commercials for it)

I believe they are supposed to be pearls. Check out this.

My goodness! You’re in polite company, have some manners, sir!