This diode is called a clamping diode. The integral diode P-N junction between the Drain and the Source of the MosFet protects this output from damage when this mosfet is used to switch motors, relays, etc., or anything else "inductive".
It is *not* a "...load (resistor) or for biasing..."
when gate and drain of a MOS are shorted the MOS starts acting as a diode. It is quite usefull in integrated circuit as there is no need for a separate mask set to fabricate a diode which save a quite a money.