Nemo the Anti-Christ

Nemo the Anti-Christ or simply known as Nemo, was a character in "American Dad!" and the main antagonist in the episodes Season's Beatings and Rapture's Delight. He was once Jeff and Hayley's adopted son that turned out to be the Anti-Christ, the son of Satan. He was voiced by Murray Miller.

In American Dad!
In "Season's Beatings", Jeff was seen bringing Nemo in the house, announcing that he'd adopt him as his own child. Hayley and Francine quickly became fond of him. However, Stan rubbed his hair and discovered the numerals "662+4=666", meaning that Nemo is the Anti-Christ. Stan had Father Donovan go to the site of the abandoned orphanage to find Nemo's papers. Nemo sensed their discovery and had the orphanage collapse on Donovan from a really far distance. Before his death, Donovan shared the information with Stan on how to kill the Anti-Christ; with 7 sacred daggers. Stan, Jeff, and Roger went to the Vatican to retrieve the daggers. Nemo discovered that Jeff and Roger were in the catacombs and washes Jeff away with a flood. Nemo was also able to possess Steve into a demonic slave. After Roger found the daggers, he and Stan returned to the house to kill Nemo. While Stan was fighting Nemo, Hayley prevented Stan by killing Nemo by shooting him even after knowing that her adopted son was the Anti-Christ. At the end of the episode, Nemo was taken in by Sarah Palin.

In "Rapture's Delight", Nemo had grown up and started a 7-year war with Jesus right after the rapture occured. He had Francine kidnapped and tied up to the ceiling. After the final confrontation, Nemo was killed off by Jesus, but was still able to shoot and kill Stan.

Trivia
He appeared to be modeled after The Riddler from the Batman series based on the design of his clothes.