Bedbug, Giant (GMU)
   Christmas Tree Monster (GMU)
   Cruel Puppet (966, GMU)
   Dryads (GMU)
   Dust Bunny (GMU)
   Eldritch Vapor (GMU)
   Frobgoblin (GMU)
   Ghoul (GMU)
   Hellhound (966)
   Jackanape (GMU)
   Lucksucker (GMU)
   Monkey Grinder (GMU)
   Nymph (GMU)
   Quelbees (GMU)
   Reaper Squirrel (GMU)
   Scarecrow (CMU)
   Skeleton (GMU)
   Spider, Giant (GMU)
   Troll (GMU)
   Yellow Grotch, Mutant (GMU)

The Forest of Youth, to the north of Gurth City is a massive collection gnarled ironwood trees, graceful stands of birches, old melancholy willows, eerie copses of twisted elms, sweet-smelling pines, ancient oaks, babbling brooks, stately catalpa trees, songbirds, and unfortunately, vicious hellhounds, and cruel puppets hiding behind trees waiting to ambush luckless adventureres--thus residents of the nearby Gurth City were warned to keep away from this sea of trees. Within this forest is the Pool of Eternal Youth, created by Eru at the founding of Zork.
Sometime during the Great Monster Uprising, a man by the alias "Detective Softly" discovered the Amulet of Aggthora in the Forest of Youth, which had been placed in a gloriously beautiful clearing by an unknown person. Here, cute critters bounced across the emerald green grass where a mighty fountain sat int he center, the spray of which catched the light and created a most singularly amazing rainbow.

Also during the Great Monster Uprising, Tandric the Trapwright had his headquarters for his gang of bandits, a very cleverly hidden treehouse, within the Forest of Youth.

SOURCE(S): Beyond Zork, Legends of Zork, Zylon the Aged