Troop

Source Bestiary 3 pg. 310
A troop is an organized collection of component creatures, typically Small or Medium in size, working as a cohesive whole. A troop is 16 squares in size and has two Hit Point thresholds in their HP entry, under which it reduces in size to 12 squares and then 8 squares. A troop has the Troop Defenses, Form Up, and Troop Movement abilities. Most troops have a weakness to area damage. Because they consist of multiple discrete creatures, they can't be summoned.

Monsters

City Guard Squadron, Hellknight Cavalry Brigade, Last Guard, Nightmarchers, Rancorous Priesthood, Shambler Troop, Skeleton Infantry, Terra-Cotta Garrison