Dying in Darkhorn

Last night I drew the surface and first level of a hypothetical megadungeon, which I temporarily named Darkhorn. The place is supposed to be the lair of a very powerful necromancer (perhaps a lich?), who expanded the underground of his tower (precisely, Darkhorn Tower) for hundreds of years. The Necromancer now dwells in the deepest levels, regardless of what happens in the higher ones. To spice up things a bit, I decided to introduce a special rule for the adventurers who may die in Darkhorn.

Dying in Darkhorn
Down in the underworld of the dungeon of Darkhorn proliferates an awful fungus, created by The Necromancer himself Orcus only knows how long ago. The fungus is invisible, odorless and tasteless, and fills each room and corridor of the entire complex. Each time a humanoid dies in Darkhorn, the fungus immediately attacks his dead body, taking control of its vital functions. Thus, the dead body rises again as a fungus-controlled avatar for a certain period, according to the type of undead it rose as. Check the table below to find out:

d20 Undead Type Period
1-10 Control Fails –
11-14 Skeleton* 1-6 months
15-17 Zombie 1-6 years
18-19 Ghoul 1-6 decades
20 Ghast** 1-6 centuries

You find this idea stupid and unrealistic? Well, check out this:

Click on the image to learn more about fungus controlled zombie ants

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*Flesh gets consumed during the process
**In levels below 5th change Skeleton to Zombie, Zombie to Ghoul, Ghoul to Ghast and Ghast to Minor Vampire (lasts eternally)