Carriers

Carriers were copper men with a black box, who attacked Carter and Sadie Kane. They would, as Bast said, "The carriers capture you, beat you senseless, throw you in [the sedan] and carry you back to their master. They never lose their prey, and never give up.

The Red Pyramid
Four carriers jog after the Kanes and Bast, who are in a silver Lexus convertible.

Trivia

 * The carriers have a black box called a 'sedan'.
 * The sedan seemed to be based off of Set's entombing of Osiris.