False Guardian

The False Guardian appears to be a wooden manikin with a pull cord on it's chest. When the cord is pulled, an illusion covers the manikin so that it appears like a soldier of the race that activated it. So, if a dwarf pulls the cord, it looks like an armored dwarf. If a goblin pulls the cord, it looks like an armored goblin.

The illusion will appear as if it is standing still, but blinking or maybe twitching a shoulder. Enough that it looks real. It won't move, though.

If the Guardian is attacked, whether by weapon or spell, it will immediately let out loud clanging noises and start flashing brightly. Anyone standing near it must save vs. spells or be stunned for 1d4 rounds.

Any creatures within sight or hearing distance will immediately be alerted to the attack. Wandering monsters may be attracted to it, along with the whoever posted the guardian in the first place.

False guardians are mainly used by military forces to cover areas of minor importance. They don't have to waste a soldier's time, and any stealthy attackers will assume the sentry is real and will probably attempt to eliminate it, with disastrous consequences. Smart commanders also place it in areas that are more exposed to special operations attacks, so that a guard isn't endangered.

Tome of Spell-stealing

This large, obviously magical book is sometimes found in treasure troves. Characters looking it over will assume it is some kind of spellbook or even holy book. In fact, it is a clever trap.

If a mage or cleric reads this book, even just flipping through it, they immediately lose one random spell of the highest level they have currently memorized. The effect is as if they had cast the spell, so they cannot immediately just memorize another spell. If they continue reading, they will continue to lose spells at the rate of one spell per round of reading.

The book can be burned or otherwise destroyed, just as a normal book can be. Some spellcasters, after realizing what the book is, will keep it among their other spellcasting materials, to punish any would-be thieves.