The Sentries' main purpose is to stand guard over military outposts and depots throughout the Kree Empire. Sentry-459 accompanied a Kree scientific party that journeyed to Earth to experiment on sub-humans. When the Kree left Earth, Sentry 459 remained to monitor Inhuman progress, so that the Kree could later use them as a militia force. Sentry-459 remained inert but observing until activated by the superheroes the Fantastic Four, who fought it to a standstill. Considering itself defeated when the Fantastic Four escaped, the Sentry sent a signal to the Kree alerting them to the presence of meta-humans on Earth and then deactivated itself. The Sentry was then transported by the U.S. Army to Cape Canaveral, where it was reactivated by the Kree Colonel Yon-Rogg, the leader of the Kree expedition then investigating Earth. Yon-Rogg hoped the Sentry would kill the hero Captain Marvel, another member of expedition. Mar-Vell, however, managed to defeat it. Ronan the Accuser later reactivated the Sentry and used it in an attempt to reverse the course of evolution on Earth, but it was once again defeated by Mar-Vell. The Kree agents attempt to retrieve the Sentry but are driven off by spy agency S.H.I.E.L.D.. The Sentry was seen again when activated by the Super-Adaptoid, who used the robot as part of his team Heavy Metal in a bid to destroy the superhero team the Avengers. It returned in the Blackwulf series, having been found by Ultron, and joins the Underground Legion but was eventually destroyed in the series finale.
Other Kree Sentries
Sentry-459 is not the only Kree Sentry of the Kree Empire. The following are also Kree Sentries:
Sentry-9168
Another Sentry - designated 9168 - was encountered by the Fantastic Four on the Moon. Only six feet tall, this Sentry was programmed to prevent any space travelers from Earth from finding the remains of a hidden Kree city in the Blue Area of the Moon. The Fantastic Four battle and destroy the Sentry via a remote destruct mechanism.
Sentry-213
This tall Sentry was stationed in an unmanned supply depot/surveillance post on the planet Uranus. It was destroyed by a group of Eternals led by Uranos, sparking a war with the Kree.
Sentry-372
This Sentry only appears once, and battles several members of the Shi'ar Imperial Guard before being damaged by the West Coast Avengers. The Sentry then self-destructs and destroys the outpost it was guarding.
Sentry-571
This version aided the Kree when their "Lunatic Legion" attacked Earth. It was defeated by Iron Man.
Powers and abilities
Being a robot created by the Kree, the Sentry has Super Strength and durability, Magnetism and Energy Projection
In other media
Television
The Sentry-213 version of the Kree Sentry appears in the Fantastic Four episode "The Sentry Sinister", voiced by Mark Hamill.
Sentries appeared in the ' episode "Trial by Fire". Ronan the Accuser accused Johnny Storm of destroying several Sentries.
The Kree Sentries appear in ' episode "459".
The Kree Sentries appear in the Avengers Assemble episode "Captain Marvel." They are used by the Kree soldiers led by Galen-Kor in their plan to capture the recently emerged Inhumans and a bonus mission to capture Captain Marvel.
Video games
A Kree Sentry appears as an assist character in the 1995 arcade game Avengers in Galactic Storm.