Generating Non-Standard Undead

As part of my slow-burning Saltbox project, I’m working up material on ghost ships.  I think of them in three categories: Ships with divine purpose (La Grande Chasse Foudre, or a more malign analog), ships of cursed undead taking their anger out on passers-by (Flying Dutchman, or the Black Pearl), and boats of monsters that want to eat your face.  Since I’m usually working with either B/X or ACKS (with occasional recourse to the SRD), this breakdown organizes undead monsters like so (this is ACKS, which gives Ghouls an extra HD):

Since I’d also like to present the population of ghost ships in terms familiar to descriptions of ship crews in these rulesets (“there is a Nth level fighter for every X pirates…”), I’m interested in being able to target the gaps in that chart: If I have a ship of ravenous undead captained by a 6HD creature, what is it?  I could just fiddle with the HD of existing creatures, but I’d like to be a little less predictable.

Instead, I’m taking the target HD, using a base attack damage of 1d6, and calculating the armor class of the creature as 8-HD (for B/X) or HD + 1 (for ACKS).  Then I’m rolling as indicated on these tables for special abilities and quirks of appearance (forgive the slight maritime bent):

 

I expect that the entries will get weirder with use, but I like the way the captains are shaping up so far. As is, they come fairly close to generating the traditional undead monsters as possible outcomes, which I regard as a virtue.