Kriegaffe

The Kriegaffe ("Kriegsaffen" meaning War Apes) were a series of mentally and physically enhanced apes created by Nazi scientist Herman von Klempt. Most Kriegaffen can be seen with cybernetic arms and metallic appendages on their heads.

Brutus
During the events of World's Greatest Paranormal Investigator (CBG), Herman von Klempt and his Kriegaffe # 9 (whom had been dubbed Brutus) had been hiding out in a castle, and performing experiments on kidnapped peasant girls. The duo was stopped by Hellboy when he interrupted one of their experiments. In the ensuing battle, Hellboy destroys Brutus' hands, and burns down the castle, saving von Klempt's only remaining victim, and killing Brutus.

Kriegaffe #10
A tenth Kriegaffe appears in the Conqueror Worm story arc. aiding Herman von Klempt, and Inger von Klempt in their attempt to unleash the Conqueror Worm. After von Klempt captures Hellboy, Kriegaffe #10 repeatedly tortures him until the bases power shuts off, and Hellboy defeats the brute. Kriegaffe #10 attacks Hellboy again, but is defeated, and apparently killed.

Years later, the skeleton of this Kriegaffe is seen in Hunte Castle by Kate Corrigan and Bruno Karhu, confirming that Hellboy did in fact kill the ape.

Kriegaffe #2
Kriegaffe #2 appears in B.P.R.D. 1946.

Unnamed Kriegaffe
An unnamed Kriegaffe (presuemably Kriegaffe #1) appears in B.P.R.D. 1946.

Trivia

 * Although Kiriegaffe is to be German for 'war ape', but Kriegsaffe is more correct.
 * The Unmensch had similar cybernetic limb replacements as the Kriegaffen.