#Dungeon23 Tomb of the Vampire Queen, Level 11, Room 26

 A portal in Area 26 is similar to the one found in Area 25. From this one, a horse-headed demon comes out.

This is a Mezu Demon, a type of Yokai demon.

Mezu Demon (Yokai)

Armor Class -1 [20]
Hit Dice 8* (36 hp)
Attacks 2 claws (1d8+6, 1d8+6), 1 bite (1d10+6)
Special Magic resistance (45%), darkness, immune to poison.
THAC0 12 [+7]
Movement 120’ (40’)
Saving Throws D8 W9 P10 B11 S12 SS 8 (8)
Morale 12
Alignment Chaotic
XP 1,750
Number Appearing 1 (1)
Treasure Type C

Mezu demons are low-level, but powerful horse-headed demons that have two purposes, keep people out of hell nad keep those in from coming out. 

They are very strong (22 strength). They can use weapons but prefer to use their claws and bite. Their heads are horse-like, but filled with sharp teeth. 

They can gate in 1d4 Mezu Demons or 1d4 Jigoku Demons (similar stats, but with Ox heads). Gating them in comes with an obligation of future service, so the Mezu will not gate them in unless the Hóu Yaoguai is with the party.

If the party has the Hóu Yaoguai demon with them they will attack each other. The Yaoguai and the Yokai are ancient enemies. This is true is the Mezu is with the party when encountering the Hóu.