These were illustrations for a small book for the German RPG The Dark Eye, published at Ulisses Spiele. There is a version of The Dark Eye were you can play cats as characters.
One of the heroes of the book ascending from the sewer. This is a fighter cat.
The fighter cat from the illustration above looking for some new weapons on the cat market
A gang of bad cats awaiting the heroes
One of the heroes secretly listening to a conversation
One of the heroes in danger - but not really. :D
Vignette: A mad rat
Vignette: Some seagulls fighting over a dead fish