Barrier-bots

The Barrier Bots guard the entrance to the Near Death Star. In 3001, they only let Fry in, thinking him to be Professor Farnsworth, when he provides them with a tissue sample (courtesy of Cubert), and impersonates an old man, and later, when Fry, Leela, Bender, and Cubert escape the Sunset Squad Chasers, they break off the arm of one of the Barrier Bots.