The Rat Trap

Dr. Hölzer's took it upon himself to build a better rat trap. One which like a cat needed no re-baiting and resetting each time a mouse was caught. Hölzer's Rat Trap could hunt it's prey and was surprisingly fast and agile. It was quite an efficient rodent eradicator, in fact it could catch and eat just about anything. It's appetite was insatiable and it only took live prey. Lucky for us Hölzer made them sterile.

The Bird Woman

This is a failed but interesting experiment at producing an angel-like creature. Instead of a female body with wings on her back the scientist ended up with a female body with the head of a very difficult to identify bird. Lügner claimed he wasn't asked to bring back the name of the bird who's genes he collected for the experiment. In addition, Hölzer didn't keep very good records.
This unfortunate bird-brained creature had an extreme fear of it's keepers and attacked them any time they came close to it's cage. A strike from it's beak could be deadly. It's shrill, rasping cry was the right frequency and loud enough to shatter laboratory beakers and flasks in the building next door.

Hard-Head

This specimen was the product of an attempt at creating a worker for hard-hat conditions, with a built-in hard-hat. This 'bonehead' wasn't entirely successful, being barely intelligent enough to feed itself. It's head was actually bulletproof but it's extremely large eyes, which lacked eyelids, were quite vulnerable. Hölzer thought the proportionally larger legs would be an asset to the worker he was designing. Lügner doesn't elaborate on that aspect.