Sentry

Sentry-459 is a fictional character that appears in the Marvel Universe. It is one of series of humanoid robots built by the alien race the Kree. The character first appeared in Fantastic Four vol. 1, #64 (Jul 1967) and was created by Stan Lee and Jack Kirby. 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 (which in turn created the race the Inhumans). 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 Kree Accuser Ronan the Accuser... full article at wikipedia