I'm fond of Wilbur Smith's novel and that story was utterly outstanding. Whilst I cannot possibly top it I can offer the following little tale in a similar vein.
Many years ago when I was about 18 I was holidaying in Northumberland and went fly fishing with a friend on the Coquet near Warkworth. Unfortunately, my total pain in the ar*e, gobby little brother (aged 16 at the time) insisted on tagging along, and mother insisted he be allowed to come with us, much to our disgust. Making our way along the river bank to my favoured spot we found that since our last visit sheep had been put out to graze and the farmer had placed an electric sheep fence in our path. Not too high, so my friend and I stepped over it with no problem but mouthy little git was - and is - of considerably shorter stature and had to stand on tiptoe to get over. As he was half way over my mate and I exchanged glances that spoke of revenge so I carefully placed the tip of my split cane fly rod (carbon fibre was but a dream then, thank god) under the wire and gently raised it a couple of inches. I suppose the effect was similar to the rhino's reaction, little snotnose shot skywards, easily clearing the fence and dropped to the ground clutching his nuts whilst screaming "ah'll tell me mam you bas*ard!", which he did very promptly when we got back. However, it was worth it as the little bugger kept well away from us for the rest of the day apart from the occassional snivel and never, ever came fishing again.
Gordon