Planet of the Cows

At the very beginning of the 1987 TV series episode Planet of the Turtles, Leonardo, Michelangelo, and Raphael's viewing of a alien turtle wrestling match is interrupted when Donatello tinkers with the Turtlevision device made to tune into different dimensional frequencies, citing a solar flare as interference. The TV briefly goes to a show with anthropomorphic alien cows dancing, and declares that the show is from the Planet of the Cows.