Dan Halen is the overall main antagonist of Squidbillies. He's a rich, maniacal, treacherous, ageless, eccentric, resourceful, remorseless, chaotic, warmongering, power-hungry, insatiably greedy, and incredibly cold and calculating as well as extremely cruel, narcissistic, unmerciful, sadistic, manipulative, businesslike, inimical, dangerous, malevolent, amoral, and conniving minion-of-darkness and resident of Dougal County. He is the owner and Chief Executive assistant of Dan Halen Sheet Rock International, and was the CEO, until he hired Early Cuyler as the corporate fall guy to accept liability for his recklessness, e.g. certain class action lawsuits which may or may not, and currently are in litigation, in perhaps the most memorable episode from the first season.

He is super intelligent; this is chiefly manifested via his formal 'English' accords, manner-of-speech, and literary eminence. In that respect, he is similar to Sideshow Bob, from The Simpsons.