More-seriously though, a biological example of an AGI would just be a regular old intelligence. You are (presumably) human and intelligent, and therefore have instantiated the intelligence algorithm on a biological substrate. You might argue that we are not actually general intelligences, especially when not caffeinated. I think this is a bit of a cop-out and we all know what we're talking about here :)

Just as birds proved that heavier-than-air flight was physically possible, humans prove that you can make matter perform as though it is intelligent.