If the rear valve cover is leaking profusely, it can run down the backside of the engine.
The clutch push rod seal and/or the output drive shaft also commonly fail. However, they usually drip near the side stand. Some may blow back to the wheel, but likely would not reach the hugger.
Lastly, I have seen (read about) an oil leak from between the engine case halves at the rear of the engine. In that instance, the engine had been removed from the frame and reinstalled incorrectly. I don't remember the details, but the cases were improperly stressed. In turn, the split between the case halves opened and oil would leak out at the rear.