Character: sweepy
Sweepy is the nickname given by White Forest Rebels to a Vortigaunt janitor first seen sweeping the floor at the City 17 Trainstation at the very start of Half-Life 2.
Sweepy is seen again in White Forest's Silo 1, sweeping a very dark room with a broom at the foot of the rocket, then again sweeping the floor on ground level after the valley battle.