A table of wandering monsters courtesy of the Table of Many Tables.
1. Shambling Hogweed. One of the worst, most formidable monsters you will ever encounter. Not fun. Frequency: Very rare
2. Vampire hat. Number Appearing: 1-100.
3. Ineffable Hovering Sphere of Inescapable Terror with One Big Scary Eye and Lots of Smaller Scary Eyes. Armor Class: 1 ; 4 ; 8 
4. Brain-Eating Cuttlefish-Headed Psi-Tyrant. Move: Average.
5. Rockslider. Hit Dice: 9 (foreign), 12 (domestic)
6. Boulet. (Pronounced "bull-lit") Treasure Type: Y
7. Living House. % in Lair: 100%
8. Action Mold. No. of Attacks: 1 or 10
9. Pixie, Feral, Giant. Damage/Attack: 3-12
10. Lobstormer. Special Attacks: Summon a storm of lobsters 1 time/day
11. Pangolin, Giant. Special Defenses: Can roll itself into an impenetrable ball
12. Creepy Crawly, Standard. Magic Resistance: Standard
13. Giant, Quarry. Intelligence: Low
14. Hobnoblin. Alignment: Neutral evil
15. Eel Magistrate. Size: M
16. Beige Slime. Psionic Ability: Nil
17. Flying Calamari. Psionic Attack Mode: ?
18. Golem, Bread. Psionic Defense Mode: Nil
19. Cavy, Dire. Note: Rarely tamed except by ringwraiths or nightgaunts or whatnot
20. Primordial Blah. Description: Indescribable. And unknowable. And unspeakable.