Invader Stek is an Irken Invader who was born around the same time as Invader Zim, and graduated in the same class as Invader Mez, who he had already parted ways with. Stek was also acquainted with Invader Dingz, but they never really got too close.
Stek never enjoyed the company of other Irkens, and doesn't tend to speak much. He is extremely violent, cold, and calculated.
Stek has red eyes and a vertical scar stretching over his left eye. He wears a black trench coat with red trim, and a custom PAK given to him by Invader Mez. Stek also has a special sense enhancement module on one of his antennae, which was also given to him by Mez, is well known for his proficient skill with the M.O.P, which was invented by and given to him by Mez as well.
Stek was born with a slight defection: he had female-like antennae and a strong rebellious will (unusual to smeets). However, Stek was allowed to live because of his exceptional performance in the military academy.
Stek not only displayed physical superiority, but also mental superiority. He excelled in scientific areas of study, but never really was interested in them. Stek was more invested in military strategy, combat, and weapon design. Stek was noted to have invented several things, but he never shared them with anyone else.
Despite Stek's great capability in the academy, and was taller than most of his peers, he was still bullied by his classmates for his "girly" antennae. It didn't help that Stek had such a bad temper as well (although he never really showed his emotions), and because of this, he was responsible for over 135 in-class injuries. You'd think that after gaining such a reputation people would leave him alone, but Stek could never seem to go anywhere without running into someone who thought his antennae were funny. Thus, Stek never enjoyed much company.
The only Irkens Stek really enjoyed (or maybe tolerated) seeing were Invader Mez and Invader Dingz. He made friends with these two Irkens during his time at the military academy mainly because they were outcasts too, and he felt a need to protect them, as they were not as strong as he was. Out of the 135+ injuries that Stek caused, about 72 were in defense of his friends.
However, Stek's state of friendship didn't last long; Invader Mez was tired of being small and weak, and he decided he was going to find a way to change himself biologically. He succeeded in his task, and as a result, grew to about the same height as Stek and nearly stronger. Stek now began to observe Mez more and more as a threat rather than a friend. Mez also began to change, becoming more arrogant and independant, wanting less and less for Stek to assist him in day to day tasks. Eventually, the rift between these two had grown too big, and there was a large fight between them one day, starting off verbal, and reaching physical attacks. Following the day of the fight, Mez and Stek became rivals, and parted at the time of their graduation. They would go on to occasionally clash in their later careers. Stek also parted with Invader Dingz on that same day.
The origin of Stek's scar over his eye is relatively unknown, but there is rumor that the injury was acquired during an in-class experiment gone wrong, which was caused by Invader Zim, and affected Invader Mez as well.
Not much is known about Stek's later career, and he hasn't been spotted for years. He was last seen around planet Earth about two years ago, but is not believed to be on the planet's surface currently.
Stek was always an inventor of sorts, but never publicized any of his creations. Anything that he might have made is unknown.
It is believed that Stek was snatched up by the S.A.F.I.R, but it's really unknown what happened to him. He may have died, for all the common Empire knows.