Fendlesworth is one of the pseudonyms of a promiscuous and vexatious commenter on such blogs as Respectful Insolence, LeftBrain/RightBrain Autism, Starts with a Bang, and Just the Vax. His real name is Travis J. Schwochert.
His modus operandi is to start with a slightly off-base comment, and then when challenged, degenerate into scatological and or childish ways to incite the commentariat. When banned, he attempts to slide back in by using fake names and email addresses.
One particular new wrinkle is impersonation. Travis J. Schwochert looks through approved comments and then scours the internet for an email address that might match that commenter.
Travis J. Schwochert may be a classic troll: someone who just gets off on causing chaos in a commenting community. According to my sources, he's also used the 'nyms Soren Kongstad and Lars Ørnsted (both of whom are probably real, upstanding Scandinavian citizens.)