I showed this figure in the group shot in my recent skeletons post but looks like I forgot to include the individual shots of him. I've seen a few mentions of him recently on other blogs. I was able to help out a fellow blogger who was after one as I located a spare, and Jeff of Jeff's Gameblog made a post detailing some alternate rules for him. Funny that, because I also chose to make a new monster type for him as I wanted to use him in the game and a Lich was too powerful an opponent for my level 1 adventurers. I wound up calling him a ghostly summoner which, come to think of it isn't such great English as ghostly must refer to the manner of summoning and not his own state. Maybe undead-summoner is closer to the mark. Anyway, moving forward I can add both undead-summoner and trumpeter of doom to my encounter tables. Thanks Jeff! I'm all for getting some added mileage out of my figs and keeping my players on their toes.
Spoiler alert: my players, you may want to skip this.
In all honesty when this guy showed up in the game I had still not worked out every little detail. I basically intended him to be a kind of guard dog that could pass through walls while doing his rounds and summon a group of 2d6 skeletons each time he blew his horn. He will then stay out of the fray and bring reinforcements (limited times per day or would some action on the pc's like turning or a spell cause give his horn another charge? A d6 roll to see what trigger will recharge the horn?). He is immune to non-magical weapons and so will pose a serious barrier/danger to a starting group. He acts like your basic ghost in a movie, not fully aware of his surroundings until you get up close. Think the librarian ghost in Ghost Busters. So, while he's wandering the halls he can be avoided more easily than, say, the same wondering band of 2d6 skeletons that he's set to unleash. Plus, there is that sense of the unknown you get when you wrap a familiar monster like a skeleton in a new guise (a guise that the players will likely think is a much more powerful entity e.g. lich, spectre, ghost, etc). Oh, and the first blast o' the day also acts as a protection from good +1 spell as cast by Cleric level 2. It is turned as a shadow, has three hit dice and attacks only rarely (will usually retreat before this is needed of players have magic weapons) with a dagger and leaves behind his horn as treasure when vanquished, which turns invisible in one turn. It will remain where it lies in the ethereal realm until retrieved by a creature capable of doing so. Maybe there is a spell or combination of spells that can make it corporeal or allow it to be stowed in its ethereal form (suggestions?).
As always, my D&D collection can be viewed in its entirety at flickr.