The only stats I know of are from previous editions, in Dieties & Demigods/Legends & Lore under the Celts.
Here's the 2E versions of the master and hounds of the hunt:
The Master of the Hunt
The Master appears as a dark skinned man wearing an antlered black helmet.
Role-playing Notes: The master does not speak or communicate with anyone. He merely leads his pack of hounds and other followers toward sources of evil and attacks. His tactics are generally limited to an immediate frontal assault since he cannot die, his need for cunning is limited.
Str 18/00 Dex 18 Con 18
Int 17 Wis 17 Cha 9
MV 18 SZ 6’ MR 25%
AC 0 HD 20 HP 200
#AT 3 THAC0 1 Dmg 1d6 +3 (spear) +6
Special Att/Def: The Master of the Hunt generally does not engage in combat until most of his pack of hounds have been slain. He will then attack with his spear +3. The Master can also ride his chariot over victims, doing 3d10 points of damage to any who fall beneath its wheels.
The Pack of the Wild Hunt
The individual hounds of the Wild Hunt are beasts. There are 20 dogs in the pack.
AC 2 HD 5 SZ 3’
MR 15% THAC0 14 HP 30
MV 21 #AT 1 Dmg 2d4
Special Att/Def: The pack can cause fear in any mortal being that it is pursuing. Each hound has the equivalent protection from evil spell upon it at all times. The pack also can swarm its enemies without regard to the actual space available, so all 20 dogs can attack an enemy each round. Finally, once per turn each dog can use its green flame tongue to add an additional 5 points of damage to any attack that hits.
Here's the text on the hunt:
The Wild Hunt
Despite its evil connotations, the Wild Hunt is a manifestation of good life force on the Prime Material Plane. It appears in Celtic lands whenever there is a great force of evil in the area. The source of the evil could be many different things, from an evil wizard or priest moving through the area to an invading evil army. Wherever the druids are and wherever they have built standing stones that the Wild Hunt can use as beacons, the pack and its master are forever on guard against encroaching evil. The Wild Hunt appears in the world of men as a huge pack of magical dogs led by a great man. The man has dark skin and can either be on foot or at the reins of a two-horse chariot. He carries an enormous spear and wears a metal and leather helmet with antlers. The dogs of the pack are huge beasts that can, at one instant appear as normal (albeit huge) canines and then transform into ferocious, magical animals with green flame coming from their mouth and eyes. When the Wild Hunt approaches, the weather turns for the worse — the winds howl and thunder booms from the heavens. The Wild Hunt fights evil with evil’s weapons, namely fear and ferocity.
Celts or other good beings who encounter the Hunt on the move may be swept up by it. All Celts or characters of good alignment who see the Hunt must make a save versus spells or become part of the Wild Hunt and its mission, accepting the Master as their leader. Persons so caught up might have to act against their own alignment at the behest of the Master, fighting against those they might otherwise ignore, etc. As it tears across the countryside, the pack will raise a terrifying ruckus, attracting followers and warning evil of its approach.
On any given night there will be only one Wild Hunt, provided there is sufficient evil to warrant it. Once the pack has caught up with the source of evil, it will attack. The pack and the master will fight to the death against the evil. If they are slain, they will appear fresh for a new hunt the following night. If they do not destroy the evil they pursue, the Wild Hunt will return until their prey is driven from Celtic lands or slain.
The Wild Hunt has been known to fight against demigods and heroes who have manifested evil among the Celts. Sometimes destroyed themselves, they have always returned to renew the battle. The forces that seek out evil to destroy it are eternal, and the Wild Hunt can never be completely annihilated.