Blaktoof

Blaktoof is the Overfiend of Octarius, an Ork empire at the center of one of the biggest xenos battles in history.

Official Canon
Blaktoof was Overfiend of the Empire of Octarius by the time Hive Fleet Leviathan reached the region. This war is in a never-ending stalemate as both Orks and Tyranids are extremely numerous and constantly adapting their tactics to each other.

TTS Canon
Blaktoof is seen being soundly defeated by Ghazghkull Mag Uruk Thraka for dominance of the Octarius system. Despite this, Blaktoof refuses to surrender, amusing Thraka. He is spared so that Thraka might enlighten him with the word of Gork & Mork.