Them’s Fightin’ Herds is built in Z-Engine, a proprietary fighting game engine made by Mike Zaimont (Lab Zero) for the development of Skullgirls. In March 2014, Lab Zero completed a successful Indiegogo campaign for their Skullgirls 2nd Encore DLC, during which they attained a stretch goal for $725,000 USD that stated they’d license the Z-Engine to Mane6 free of charge.
Mane6 launched their own Indiegogo campaign for Them’s Fightin’ Herds in September 2015. The project was successfully funded with a total of $586,346 USD. Stretch goals attained included ports to macOS and Linux, a seventh playable character (a goat), as well as a stage and Story Mode chapter based on that character.