Bestigor
From Warhammer - The Old World - Lexicanum
Bestigors are the largest and most ferocious Gors of a horde, and are also better equipped with armour and better weaponry - for example helbeards. Units of bestigors can also take specific marks of chaos, and as such gain bonusses attributed with their patron.
In the most cases the Chieftain of the War Herd comes from this breed.
Bestigors for the game of Mordheim
In gaming Terms:
Bestigors are a core choice in a Beasts of Chaos army.