Samuel Aboah was a teliko who traveled to the United States from Burkina Faso. He lacked a pituitary gland and assaulted African-American men in Philadelphia to replenish his hormones after disabling them with a blowdart (though it is worth noting he didn't actually have to target African-Americans specifically, he just decided to use them as his preferred victims, making him a form of serial killer).

In this manner, he murdered five men and nearly killed his INS agent Marcus Duff and Agent Mulder. Aboah was subdued after being shot by Agent Scully and was to be tried for five counts of murder, but there was doubt that he would even survive long enough without hormonal replenishment to be tried.