The Rainbooms, the Turtles, and the Mighty Mutanimals go dimension hopping and land in a world populated by anthropomorphic animals living in an old Western setting. They decide to stick around and help a trio of law abiding cowboys protect their town from outlaws and other lawbreaking miscreants. Join the heroes who become the Ninja Cowboy/girls of Moo Mesa.

Contains no spoilers from Equestria Ninjas Friendship School