Grunion classified in the family Atherinopsidae along with other New World silversides including the jacksmelt and topsmelt. The California grunion, "L. tenuis", is found along the Pacific Coast from Point Conception, California, to Punta Abreojos, Baja California Sur. They are rarely found between San Francisco in the north and San Juanico Bay, Baja California Sur, in the south. The Gulf grunion, "L. sardina", is found along the coast of Baja California in the Gulf of California. Inhabiting the nearshore waters from the surf to a depth of , marking experiments indicate they are not migratory. They are small, slender fish with
Creature Catalogue of the player characters, originally printed in the Master Set, is reproduced in the introduction. Each creature is listed with appropriate "D&D" statistics and a short description of the creature, its abilities and tactics. A variety of authors and artists combined to the listings including Zeb Cook and Gary Gygax. AC9 "Creature Catalogue" was compiled by Graeme Morris, Phil Gallagher, and Jim Bambra, and was published by TSR in 1986. The "Creature Catalogue" is in the format of a 96-page perfect-bound book, which TSR had been adopting more frequently at the time. Cover art is by Keith Parkinson. An updated