@RoboBlue:
You can only make so many fantastical creatures designs before you fall into the Digimon trap of having hundreds of werewolves, robots, dinosaurs and demons.
Real life is more creative than fiction.
I'd say it's more correct to say that they're just not truly original.
They're still creative in the sense that even though they do retread familiar creatures, they do so distinguishing them with different stylized fashions or mash-ups.
Comparing the entirety of planet Earth's pool of living and extinct animals, in its billions of years of biodiversity, to a single series with a particular aesthetic driven by merchandising that has to fit its creations into narrative, character, and gameplay roles, you'd still come out more wolf and dinosaur species compared to their respective Digimon counterparts and it's not hard to see why.
For the more popular species, you'd start beating them out when you start stacking many creative sources together, unless you circle back to the most diverse of things, microorganisms.