Lady Gaga appears to believe Katy Perry is aping her ideas by donning green hair and riding on horses on tour, and took to Twitter to take a shot at her.
The Mother Monster tweeted to her fans: "It looks like green hair and mechanical horses are the thing now," along with the emoji of a pair of googly eyes.
Katy Perry kicked off her world tour at the Odyssey Arena in Belfast, Northern Ireland, riding around on a mechanical horse and sporting green hair.
Gaga, who has been vocal about being kind online, made quite the entrance at the American Music Awards when she arrived on a giant, fake white horse.
The ARTPOP diva also has neon green hair now, for whatever that's worth.