Obviously an anti-hopping clutch won't make the motorbike hop. How is this achieved? What are the mechanical and functional differences between a normal and an anti-hopping/slipper clutch?
On a regular clutch, the inner hub that drives the gearbox is a single casting. Clutch plate pressure is solely applied via the outer pressure plate and springs.
On a slipper clutch, the inner hub is composed of two pieces that engage via dogs (the same way a bike gearbox/transmission works). The dogs have a flat driving face and a ramped face. Under normal driving conditions (engine driving the rear wheel) the two-piece hub acts like a normal clutch. However when you back the throttle off and you get back torque on the rear wheel, the slipper comes into play. This causes the ramped faces of the dogs to push the two pieces apart and reduce the pressure on the plates allowing some slippage and stopping any rear wheel lock-ups or hopping.
A picture speaks a thousand words (courtesy Yamaha)
One side note, do not take any notice of the Wiki definition. It is a complete mish-mash of information and confuses terms between a slipper clutch as on road bikes and drag racing slider clutches that are sometimes also referred to as slipper clutches. They work in completely different ways.
With a normal clutch the plate or plates are either locked or separated depending on whether the pedal/lever is engaged or not. The clutch pedal/lever also controls how much the clutch will slip at various pedal/lever positions.
A slipper clutch is locked when forward drive is required. However when off throttle the clutch friction plates are allowed to slip as spring pressure separates them and allows an adjustable amount of drag.