I have been looking at the beast family of monsters and noticed that it is rather small. Only 5 types (including both snarby species). This means that there are only 3 non-boss beast monster groups.
Most are small or decent sized creatures.
Why not introduce a new kind of monster? Perhaps a crab species?
One that is slow and bulky and blows bubble bullets to stun knights so it can slam them with its claw?
http://www.mikedelaney.org/images/Img49.jpg
Another smallish fast one with a cloak and recon shield that waits till the right moment to snap at you? http://www.nps.gov/pais/naturescience/images/GHOST_CRAB_2.JPG
A long legged one that moves quick and hits hard?
http://walls4joy.com/wallpaper/247849-crustacean-japanese-spider-crab
I could go on, but I would also like to hear you ideas on a new beast monster.
Why do I like my idea more? :S