Klaustreich

A Klaustreich (KLOW-shtrykh; Grimm: KLOW-strysh; Germ. klauen = "steal" + Streich = "prank/trick" or alternatively Germ. "Klau(e)" = "claw" + "Streich" = "stroke") is an alley cat-like Wesen. They are typically known for being jerks in the Wesen community.

Biology
When Klaustreich woge they gain piercing jade green eyes, outward pointed ears, and a feline muzzle that terminates in a pink feline nose. Their bodies are covered in light grey fur except their face which is covered in white fur.

Physically, they are quite strong, able to perform cat like leaps over a distance of several yards, and match blows with a Grimm suggesting superhuman strength. Despite having both razor sharp fangs and claws, Klaustreich prefer to use the latter in combat, which can cause massive damage when combined with their strength.

Behavior
Women often find male Klaustreichs irresistible, but it never ends well for those who fall for them as male Klaustreichs are very possessive and abusive towards their soul-mates. It is very rare for a woman to escape a relationship with a Klaustreich relatively or completely unscathed. It is unknown how they attract women, be it a physiological feature similar to Ziegevolks, or simply pure charisma. It would appear to be charisma however, as a Klaustreichs hold is nowhere near as strong or as permanent as a Ziegevolks. Monroe told Nick that it is a good idea to sleep with one eye open when there's a Klaustreich around, as Klaustreichs are treacherous and highly aggressive.

While out on a romantic get away with his Juliette, Nick encountered a Klaustreich, Tim Steinkellner, who had a Seltenvogel wife named Robin. He had originally seduced her, but started keeping her prisoner, even force feeding her, along with his cousin, Sheriff Munson. They planned to keep her until she produced her Unbezahlbar.

Monroe told Nick that in high school, he lost his girlfriend, Molly to a Klaustreich, who then got her pregnant, and she delivered his litter at prom. When she told her parents, they reported him to the police. Enraged the Klaustreich slashed Molly's face before skipping town. It is implied that Monroe killed or severely injured the Klaustreich out of revenge. The event also left him with a hatred for them.

After realizing something was wrong, and seeing Robin try to escape, Nick intervened. He tried to save her and got into a fight with Tim, who although strong, proved no match for him. Nick kicked him out of his window, and saved Robin. Nick called Sheriff Munson, unaware that he and Tim were working together. Munson arrived, and together he and Tim went after Nick and Robin.

After cutting out the Unbezahlbar, Nick was cornered by Tim and Sheriff Munson. By using the threat of smashing the Unbezahlbar, Nick was able to distract them by throwing the Unbezahlbar in the air. He overpowered the sheriff and chased down Tim, who had caught the falling Unbezalbar. Tim tripped, causing the Unbezahlbar to fly up into a tree branch and smash into tiny pieces. The two were arrested by the regional police.

Excerpt from Grimm Diaries
(By Nick Burkhardt) "The Klaustreich I came in contact with was aggressive, predatory, sadistic, and treacherous."