The Cleric in the Pot salutes him. As do I. And to make things reasonable, a d12 table to go:
The Odd Ghoul
1. Has a crown-shaped tattoo 'pon its leathery hide. Is it the missing son of the King of Lepont?
2. Has an undead parasitic worm depending from its withered belly which grants it a second bite attack. The parasitic worm has the same attack as the ghoul, but +2 to AC and only a quarter of the ghoul's hitpoints.
3. It is immobile, bound tight by a thin blessed silver chain.
4. It is missing the top of its cranium and has developed a mutated, enlarged maw, giving it a -2 to hit but double damage dice.
5. It has somehow mutated and grown leathery bat wings, while the body has come to resemble that of a monkey. Or perhaps it is just a flying monkey ghoul.
6. It is entirely a bright, glowing pink. It smells of spring flowers.
7. It is actually a living elf who has gone mad and believes himself a ghoul. The elf is dressed in such foul rags that e'en other ghouls will not touch it.
8. It has biting, blood sucking mouths upon its feet.
9. It has gems for eyes. The gems grant a paralysing gaze attack.
10. It is highly radioactive, getting within 10' of it requires a save vs. poison to prevent nausea, hair loss, weeping sores and loosening of teeth. Actually getting struck by it requires a save to avoid a lethal radiation dose, which results in death within 1d4 days. The nausea is unavoidable.
11. It is covered in faces (1d8 of them). It attaches the face of every creature it consumes to its rubbery hide, where it attaches and gains a semblance of life, forced to spend every moment carried about by its eater. Every face grants the ghoul +1 bonus hit point.
12. It is completely impervious to non-magical weapons, healing fast as a troll, for it consumed one such beast, chunk by chunk, bite by bite, paralysing it and eating it faster than it could regenerate.