Christmas Rat

He is one weird Christmas visitor -- his hair and moustache an unearthly white-blond, his voice a gruff rumble. He fills the apartment doorway. From two metal cases he produces what a boy would expect from an exterminator: Toxic roach powders and poisonous fog bombs.
But a crossbow?
Eric is fascinated at first. He''s been bored this snowbound vacation, and has already zapped about a zillion Zerg...