Just About to Overrun the Wilderness Outpost

d12
1. An army of tiny children's skeletons
2. Puny humanoids, joyous following a particularly fecund nesting season, unconsciously obey biological imperative to control population by flinging themselves into poorly considered battle
3. Disgruntled cavemen, furious over desecration of hunting grounds by intruders from civilization, muster while awaiting arrival of shaman w/titanic mastodon under holy hypnosis
4. Unprecedented gathering of slimes, oozes, puddings, jellies attracted by arrival at outpost of adventurers bearing unknown relic stolen from the Underworld
5. Company of particularly mighty barbarians rendered 100% obedient from inhalation of malign, immortal, sentient gas cloud from adjacent dimension, trapped by cosmic incident, profoundly bored, seeks entertainment via toying w/humans, engineering perpetual mayhem
6. Witch demands return of artifact stolen while on sabbatical, permanent thunderstorm positioned over outpost in otherwise cloudless sky, horde of previously-harmless forest creatures stand by to go over the walls, outpost leader orders all known adventurers hauled in for questioning, light torture
7. Following brutal exile from the Big City, entirety of metropolitan underclass, well-armed after picking over recent battlefield en route, demand entry/succor or desperate/hopeless battle
8. Refugees from neighboring, even more poorly funded, recently overrun outpost, forced into encampment outside the walls at the mercy of wandering monsters during prolonged vetting period, have had just about enough of this treatment
9. One million snakes as per Serpent God's orders, deliver cold vengeance: dissed by outpost leader when only 2nd level, Serpent God forgets nothing, forgives never
10. As feared, bandit clans finally united under highly ambitious, charismatic barbarian who systematically beat the shit out of each petty bandit lord one by one until they swore fealty, now strongholds, forts, keeps, castles must stand and deliver
11. Six-person crew of crashed spaceship seek sheltered spot to repair escape craft, near-invulnerable in powered armor, death rays mow down men-at-arms at will, zero regard for human life, just not interested
12. Half of outposts' own forces attack from within, subject to destructive madness after consuming delicious experimental food product purchased from subterranean humanoids