Mirror Beast (4e Creature)
From D&D Wiki
A mirror beast is a clever fellow, and a very cunning one at that. A beast such as this has the special power to use mirrored areas to its advantage, sinking in and out of the reflection that is your own. People are known to go mad just looking at their own reflection crudely morphing into this hideous beast and forming this monstrosity. It is everywhere and anywhere and will hunt the living until no more remain.
Mirror Beast Tactics
Mirror beasts use many unexpected twists and turns in their strategy to leave their opponent dazed and confused, then it strikes with such unpredictability that its foes don't see what just killed them.
Mirror Beast Lore
A character knows the following information with a successful Arcana check.
DC 15: You know that mirror beasts do not walk, they hover, prohibiting any ground-based ensnaring attacks. also it's aura prevents 1 range attacks.
DC 20: Mirror Beasts can use Mirrored Surfaces to their advantage, coming form any angle their is one. They are actually damned humans who have had the curse of the gods upon them. Any Mirror Beast may bestow this curse on any human or creature, Elves, Dwarves and the like are immune to the curse.
DC 25: Mirror Beasts are extremely weak to poison.