From Grimm wiki
Blutbad
A Blutbad is a wolf-like Wesen species known for its predatory nature, heightened senses, and historical rivalry with the Grimm lineage.
Physiology and Behaviour
A Blutbad is a canine-like Wesen that undergoes a transformation known as woge to reveal sharp teeth, glowing eyes, and a body covered in fur. They possess immense physical strength, heightened senses of smell and hearing, and a natural pack mentality. While historically feared for their violent tendencies and predatory instincts, many Blutbaden live amongst humans by suppressing their darker impulses through medication or disciplined lifestyles.
Relationship with Grimms
For centuries, Blutbaden have maintained a complex and often adversarial relationship with Grimms. Due to their aggressive nature, they were frequently hunted by Grimms, leading to deep-seated ancestral fear and animosity. However, the bond between the Grimm Nick Burkhardt and his ally Monroe demonstrates that this dynamic can shift from hostility to profound loyalty and friendship, challenging the traditional roles defined by their respective species.