These have been an occasional nuisance in my campaign since the mid 80's, they're an infrequent but occasionally abundant pest species. They aren't based closely on anything on folklore or in nature, but there is a story behind why they're in my game. Although I'm not going to share it. Its too gross.
Dropper Beetle
by Cab Davidson
| Stat | Dropper Beetle |
| AC: | 5 |
| HD: | ½ |
| Move: | 60’(20’) |
| Attacks: | 1 bite |
| Damage: | 1d2 |
| Number Appearing: | 1d100 (2d100) |
| Save as: | NM |
| Morale: | 2 and 12 |
| Treasure Type: | U |
| Intelligence: | 0 |
| Alignment: | Neutral |
| XP Value: | 5 |
This 1’ long beetle is rarely of any concern individually. It is flattish, brown, shaped rather like a dinner plate with a tiny thorax and small mouth. Alone, a dropper beetle is unlikely to be a threat to anyone. They are rarely found alone. They gather in vast numbers, and together they patiently await prey.
They typically like to sit on the underside of cavern ceilings or under the branches of mighty trees in ancient woodlands. When they sense movement underneath them, they drop on to it and attack (surprising on a roll of 1-3 on 1d6). Individual droppers will flee if damaged, but this has no impact of the behaviour of the group, who will ignore fleeing damaged beetles and continue an attack on any live prey until it is dead.
While potentially dangerous in groups, they are slow and can be evaded by most cave dwelling species. They will not approach within 5’ of an open flame, and they can be fooled into attacking foes the have no chance of defeating (such as gelatinous cubes). Many humanoids hunt them for food, and they are particularly esteemed by kobolds.