Demand curve of a giffen good?

A Giffen good is a good whose consumption increases as its price increases. (For a normal good, as the price increases, consumption decreases.) Thus, the demand curve will be upward instead of downward sloping.

A giffen good has an upward sloping demand curve because it is exceptionally inferior. It has a strong negative income elasticity of demand such that when a price changes the income effect outweighs the substitution effect and this leads to perverse demand curve.