If you found the Frogs vs. Turtles amusing, I can put together some others. Potential warring parties:

Bunnies
Insects and crustaceans
Fish
Felines
Canines
Mustelids
Chickens and ducks
Birds of prey
Dinosaurs
Songbirds
Snakes and lizards
Dinosaur skeletons
Weird prehistoric critters
Primates
Squirrels and mice
Salamanders and newts

(and yes, I am working on new art. There should be a large art dump some time next week.)