There's something inherently weird about cartoons. Adults produce these series for kids, but grown-ups don't generally receive the same stimulation from the material. Because of this, they'll sometimes inject something – anything – to make the shows more engaging. During the early days of Cartoon Network, the channel often blurred the lines between entertainment for children and adults. As a result, there are some unsettling Powerpuff Girls characters.
Mojo Jojo is a hyper intelligent, green-skinned, mutated chimpanzee who wears a purple cape and white, high-heeled boots with matching gloves. He also loves building model ships. Despite these eccentricities, Mojo Jojo is far from the weirdest PPG villain. Some of the bad guys are wildly inappropriate for what is ostensibly a children's show, some are bizarre given any context, and some are just straight-up offensive.
Roach Coach is basically Carl from Aqua Teen Hunger Force with an affinity for roaches. In fact, he's a robot controlled by a roach, hence the name of the episode "Insect Inside." He controls roaches and fights the girls with an army of the disgusting creepy crawlies.
This is a very real Powerpuff Girls character, and his name somehow made it past the censors. Dick Hardly is Professor Utonium's college roommate, a womanizer, and an all-around terrible person. He attempts to create his own Powerpuff Girls, and winds up with "the Powerpuff Girls Xtreme," horrifying mutants with shortened life-spans. He tries to replicate Utonium's work, but his malice and resentment ultimately leads him to failure.
The Salami Swami is an amalgamation of several offensive stereotypes. He's a Middle Eastern man who wears a turban and flies on a magic carpet, playing his snake charmer's flute. However, instead of charming vicious reptiles, he charms sausages.
Toilet Mouth is a giant monster with a toilet head and a toilet paper tail. In the episode "Curses," this villain gets flushed by the Powerpuff girls for having a potty mouth. They defeat him by washing his mouth out with soap, of course.