Dr. X is the antagonist of JumpStart Adventures 5th Grade: Jo Hammet, Kid Detective. He was a brilliant scientist in the studies of biology who discovered the link to the temporary, yet successful, cross-species communication, which consists of certain animals and a neurotransmitter in the human brain, and his many experiments included talking rats and psychic octopus, which he used to wear on his head to communicate with. However, during the process of one of his experiments, he accidentally ate a heavy dose of radioactive toast, and hasn't been the same since that time. His insanity led to him to seeking revenge on six different factories and power plants in Hooverville by blowing them up because (according to him) they were unfair and cut his research funding. He was eventually defeated by Jo Hammet at the Boulder Canyon Dam.


Dr. X has light purple skin. The top of his head is enlarged and has three blue-green spots on one side. He wears a white lab coat and black shoes.

Personality and characteristics

Dr. X is a brilliant scientist whose studies of animal behavior have enabled such miracles as telepathy-enabling octopuses used by his henchmen and talking rats. He appears to be very unstable, irrationally obsessed with revenge, and willing to cause great destruction without regard to innocent lives that could be harmed or ended. It is strongly implied that his derangement is the result of some sort of brain damage caused by radioactivity.

In the Game

Dr. X first appears in the intro sequence. In Jo Hammet's nightmare, he enacts his revenge on the city by blowing it up. When Jo wakes up, there is a news report on the radio that says that the Hooverville Television Relay Station was destroyed by Dr. X. Dr. X has vowed to destroy Hooverville, one building at a time.

Martin, who used to work for Dr. X, explains to Jo that Dr. X was a brilliant scientist in the field of animal behavior. He discovered a link between certain types of creatures and a neurotransmitter in the human brain, enabling "limited cross-species communication". During one of his experiments, he received a heavy dose of radiation that apparently changed him behaviorally. Dr. X wants to get revenge on the companies which used to support his research, because he feels that they cut his funding unfairly.

At the end of the game, Dr. X disappears. His whereabouts are unknown, but Jo Hammet is still on his trail.


  • Dr. X's name appears in the credits of both games in the JumpStart Spy Masters series. Although he never appears in either games, he's said to be voiced by Lex Lang.


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