X-12
From Tardis Wiki, the free Doctor Who reference
Intra-Recovery Testimony Agent X-12 was an agent of the Great Houses during the War in Heaven who was stationed in 1880s Germany. After hearing a William Liebnecht story about an ambitious king, X-12 was captured and interrogated by Mister Gout. He was rescued by regen-inf. (PROSE: The Map and the Spider)
X-12 appeared as a spy in Jim Sheldrake's Imaginary Friends: The Hundred Year War. (PROSE: The Enemy of My Enemy Is My Enemy)