Search every book on the shelf.
Try "fireball", "grung", or "DC 15".
Huge Unknown, Any alignment
Armor Class —
Hit Points 264 (23d12 + 115)
Speed 30 ft.
Senses —
Languages understands Abyssal, Celestial, Common, Draconic, Dwarvish, Elvish, Infernal, and Undercommon but can't speak
Challenge 12
WDMM, p. 254