amicus
The death of Patroklos, son of Menoetius and Achilles' close friend, slightly older, from childhood, was the cause of Achilles' devastating re-entry into battle against the Trojans. Homer explores Achilles' grief in the books following the aristeia and tragic death of Patroklos at the hands of the Trojan prince Hektor (Iliad XVI).
Here Umbricius sarcastically compares the sleepless state of the drunken thug who has not yet committed a murder for the evening to that of Achilles, heroically suffering over his companion's death.