Forged in the fires of a cease-and-desist letter from Hasbro, Them's Fightin' Herds (opens in new tab) was once a My Little Pony fangame called Fighting is Magic. Developers Mane6 revived it with help from publisher Humble Bundle and the cartoon's creator Lauren Faust, who designed a new cast of four-legged fighters for it including a reindeer, an alpaca, and a dark-magic unicorn who wields the power of the Unicornomicon. Which is nice.
After two years in Early Access, Them's Fightin' Herds entered full release with a fancy 1.0 launch trailer as seen above. More than just a side-on fighter, it contains a story mode (releasing episodically), an online lobby in the style of a JRPG overworld, a multiplayer dungeon crawl mode called the "salt mines", and some pretty complete-looking tutorial and training modes.
That's enough bells-and-whistles to start a very specific band, while the fighting game at its core promises a deep system involving magic and super attacks, "juggle decay" to de-incentivize infinite combos, and GGPO netcode to reduce input delay.