Mordenkainen

Mordenkainen, played by guest star Sam Witwer, is a legendary wizard who ended up trapped in Barovia for a time.

The waffle crew first spotted him in the woods while they rescued Arabelle from drowning in a lake.

Mordenkainen accompanied the group to Castle Ravenloft. Once inside, he split off from them. He destroyed the heart of sorrow, which weakened Strahd. When the group were leaving Barovia, they caught a glimpse of Mordenkainen, who was in the form of a stag. Upon the crew's return to Barovia, Mordenkainen led a mob into the church to break up the wedding. He crushed Vasilka with Bigby's crushing hand.

D&D Lore
Mordenkainen is an NPC that has appeared in a number of D&D products since AD&D 1st Edition.

Real Life Character
When Gary Gygax, the co-creator of D&D actually played D&D, Mordenkainen was his character.

Gary himself ran characters when Rob Kuntz would DM. Rob would sometimes run Castle Greyhawk and also his own dungeon, El Raja Key, set in Rob;s world of Kalibruhn. Rob's castle was immortalized in the official published D&D adventure "Mordenkainen's Fantastic Adventure".

It is believed that Mordenkainen's name was derived from Lemminkäinen, a hero in Finnish mythology and one of the heroes of the Kalevala.

Mordenkainen's Henchmen
Mordenkainen's henchmen included: Zigby (a dwarf), Rigby (a cleric), Sigby Griggbyson (a fighter), Nigby (Bigby's apprentice) and Digby. He also commanded two red dragons named "Gorky" and "Porky". 300 dwarven followers.

The Circle of Eight
Gary had his characters and NPCs form a group known as "The Circle of Eight". In official D&D products, there is a Circle of Eight, but the members are not the same as in Rob and Gary's shared campaign.

The real life Gary Gygax Circle of Eight (+1) included: Together they lived in a place made of obsidian called the "Citadel of Eight".
 * Mordenkainen
 * Bigby
 * Yrag: A fighter, Gary's first actual D&D character.
 * Riggby
 * Felnorith: A fighter who collects swords.
 * Sigby Grigbyson: Fighter.
 * Ziggby: The leader of Mordenkainen's 300 dwarf followers.
 * Vin & Vram: Elf twins.

Products
He has had a number of D&D products named after him:
 * Mordenkainen's Fantastic Adventure (later revised in Dungeon Magazine #112 as "Maure Castle").
 * Mordenkainen's Magnificent Emporium: A book of magic items for 4th edition.
 * Mordenkainen's Tome of Foes: A book of monsters and lore for 5th edition.

Mordenkainen's Spells
In the game, Mordenkainen has created many spells, some of which appear in the 5th edition Player's Handbook:
 * Mordenkainen's Magnificent Mansion
 * Mordenkainen's Faithful Hound
 * Mordenkainen's Sword

Episodes
Episode 29 - Dark Horses

Episode 55 - Flesh and Blood