Narm Charm: Oh so much. Part of the charm of the series is Mutilator's delivery of serious lines. One man gets his arm sawed off, and Mutilator asks if he's okay, but it sounds like he's really bored.
"I've got a hole in my arm."
"These mercenaries are ruthless. I've got to get to my arm."
Old Shame: Averted. Fogel himself posted the videos online, and also runs a Tumblr account that has Mutilator comics. He's also worked on making a feature film for the character, calling it the culmination of a 20 year dream.
Sequel Gap: While not a full sequel, a new animatic of Mutilator was postedd on youtube in 2015, 23 years after the last installment.
So Bad, It's Good: There's no denying that the series is crude, but it's arguably a lot funnier because of it.