After seeing a pair of rock pythons sunning themselves on the banks of the Mvoti river a couple of weeks ago http://www.sareptiles.co.za/forum/viewtopic.php?f=137&t=23170, my friend went back to see if they were still there.
He climbed into the stormwater drain and saw what he first thought was a patternless Rock python (Due to its sheer size and the fact that rock pythons were there last time).
On closer inspection it turned out to be this massive black mamba with a girth the size of his upper arm (he is not the smallest guy either). Sorry about the picture quality, he wasn't hanging around in there for long.