The Zweihänder bestiary is small but fully functional. This is particularly interesting considering the issues that RMu has with the sheer size of Creature Law.
The philosophy is that each creature has a true name, and that is what you look it up under in the rules. Each creature also has many local names. So there is an entry for Nephilim but the may be known as Frost Giants in the north but Jotun in the south.
A creature entry is built out of a stat block of numbers and percentages that holds the same information as a character record. Below that is where it gets fun. Every creature is built from Traits, like character Talents. Each changes the behaviour in particular situations or confers some special ability.
These traits are brief but are written out in full, just a sentence or two at most. This means that you can run an entire encounter with each beast straight from the page with no flipping back and forth to check details.
It is dead easy to swap out a trait to modify a creature. For an adventure I was working on I took a centaur and swapped out its hind legs and gave it a mermaid’s tail to create the Ichthyocentaurs from the Greek myths.
The result is that a monster stat block is an entire column or half a page but everything is exposed and simplicity itself to tweak and change.
That ‘ease of change’ makes the next part make sense.
Where we have entire pages of stats for normal creatures, then normal sea creatures, then normal flying creatures etc., etc. Zwei has a single entry each for small critters, large critters, large and small man eaters and large and small insects. These six entries cover the entire mundane animal kingdom.
You want an Ethiopian Pegasus then take a large critter and slap some wings and horns on it. You want a tiger then it is a large man eater.
The players will never see the monster stats so the fact that a lion and a tiger are functionally the same is irrelevant. The big difference is that there could be a pride of lions as opposed to a solitary tiger.
Zwei has different classes of monster and there are interactions between character talents and classes of monster. Abysmal monsters come from the abyss, mutants are were once normal but have been corrupted and grendells are those perversions of the human form that includes Centaurs, ogres and other stock fantasy monster races.
It is the abysmal and the mutant monsters that really make Zwei adventures stand out from other games and settings. That is where its unique flavour is.
The provided beasts meant that I could create an entire Jason and the Argonauts campaign and only have to tweak a handful of beasts, everything else was straight off the page.
This is not strictly part of the core Zwei rules but the published has hived off all of the creation rules from making absolutely everything like monsters and profession and vehicles into its own supplement. If you are happy to use stock everything then you don’t need it but if you want to be able to built your own EVERYTHING then there is a single $15 supplement, Main Gauche, that gives you that ability.
The Zwei bestiary is very good, it is relatively small, extremely functional and wide ranging. It uses the same principle as CrL of building out of talents or traits but Zwei is prepared to accept a loss of definition in exchange for a massive gain in ease of use.
All in all I cannot fault the bestiary chapter.