Tarantuguns

Tarantuguns were Martian robots, designed to resemble Earth spiders and assigned to protect Martian facilities or attack Martian enemies. Like most Martian technology, they can be controlled by people with a sufficient portion of Martian DNA in their system. Tarantuguns guarded the Martians' underwater city, were used by the resurrected Head Alien, and were used by the Martians themselves during their attack on Earth in 2004.