Roaming Muffalo and Fly Swarms..These are cheap animal ideas. 10-30mins to make easy
A larger, slightly rarer roaming muffalo with horns. This creates the idea that the females herd up while the males migrate and control many herds over large territories, I think that's realistic. Much scarier when they go crazy. Also some baby muffalo in the herd perhaps. I posted this idea in the mods section, but I would like to see it actually implemented, its easy.
Swarms of flies, simple to draw, they function as a herd like muffalo, but faster, super low health, yet very hard to hit. They get hungry easily, and eat up food left lying in the wastes.