As they are sadly absent from the D&D Essentials Red Box, here’s a Wandering Monster Table for Dungeon Level 1. This is inspired by the one in the Mentzer Red Box and adjusted to accommodate the monsters in the new D&D Essentials version. It’s disappointing there’s no Giant Centipedes, Gecko Lizards, Cave Locusts and Fire Beetles in the newer Red Box, but …

Here is the original post:
Red Box Wandering Monster Table, Dungeon Level 1