This is a magic item I changed in the Shadows over Istivin adventure (dungeon 117). As written, it was simply an old Iron Horn of Valhalla lying in the mud in the dungeons under the guard house, "guarded" by a Reekmurk - not a very glorious place for such a valuable piece of treasure! I'd actually made this item up years ago but never used it. Hopefully it inspires someone else...
Iron Horn: Mephibosheth (Meh-fee-boh-sheth, “out of my mouth proceeds reproach”), an Iron Horn of Valhalla (semi-artefact; radiates strong conjuration): Created by a powerful frost giant; Neutral; Speaks and can read common, giant and goblin, and can communicate telepathically with whoever holds it; Int 14, Wis 10, Cha 12; Ego 7; Darkvision 60’, Listen +10, Detect Magic at will; market value 66,600 gp, weight 2 pounds.
Mephibosheth is very loud-mouthed and opinionated, especially when it has summoned forth its “barbarian horde”, which it cheers on during combat. It is even loud when it thinks combat might be likely (e.g. when the group gets to a closed door). It uses detect magic near constantly, loudly broadcasting any positive results. Once per week, when its name is pronounced and it is blown by anyone with proficiency with all martial weapons or bardic music ability (a standard action), it summons 1d4+1 Snow Goblin Barbarians (5th level). If the blower does not qualify, they are attacked by the hoard. Otherwise, they attack anyone the possessor of the horn commands them to until one side is all slain, or until 1 hour has elapsed, whichever comes first. The hoard prefers to fight in a group, is brave under strong leadership, and loves to eat horseflesh.
Mephibosheth’s Barbarian Hoard: Short and bandy-legged, this mixed group of male and female goblinoids have long arms, shaggy half-pelts of white hair, and large, loose sacs in their throats that give them a distinctly froglike appearance. They wear shabby studded leather armour and carry wicked greataxes, and each has a pair of javelins tucked in their belt.
Snow Goblin Barbarian 5: Small Construct; hd 5d12+5 (hp 43); init +1; move 40 ft. (8 squares), climb 30 ft.; AC 17 (touch 14); Greataxe +9 (1d10+4/x3) or Javelin +9 (1d4+2); Fort +5, Ref +4, Will +1; Str 16, Dex 16, Con 13, Int 10, Wis 10, Cha 6; Rage 2/day (+10 hp, +2 to hit, +3 dmg, -2 AC, +2 morale on Will saves; 6 rounds then fatigued for remainder of encounter,-2 Str, -2 Dex, can’t charge or run); Improved uncanny dodge; Booming Voice (can be heard over great distances), Darkvision 60 ft.; Climb +17 (can always take 10), Hide +6, Intimidate +5, Jump +7, Listen +7, Move Silently +6, Survival +3; Power Attack (Greataxe +5, 1d10+10/x3). Goods: studded leather armour, greataxe, 2 javelins. Languages: common, goblin.
Comments welcome - so far this has been excellent comedy value. The PC who "weilds" it hooked on his belt (it complained about being stuffed into a sack) has, so far, been too scared to "say my name and blow me", so he doesn't know exactly what sort of "hord" it can summon.