From publisher blurb: Welcome to Old School Rules: Monster Modifiers! In this small tome, we’re here to help the harried Dungeon Master on the go. You need interesting encounters; you need to keep your players guessing. Monster Modifiers will help you with both! Modify monsters to make that next goblin camp something your players weren’t expecting. I mean, who would expect a three-headed fire breathing goblin champion, right? To round things out, we’re going to give you random tables for those times when you have little preparation time and want to add some spice to an encounter. But wait, there’s more! We’re also going to give you three new spells, to allow magic-users to alter their minions on the fly. These spells could make enemy encounters less predictable, or, should the spells fall into the hands of a PC magic-user, make Monster Summoning spells more potent, flexible, and interesting.