Lady Gaga took to Twitter on Thursday to blast Katy Perry's Prismatic tour ... for copying her "unique" style.
"It looks like green hair and mechanical horses are the thing now," she posted on her page.
The "Dark Horse" singer kicked off her tour in Northern Ireland yesterday, and judging from the photos, Katy's mimicking some of Gaga's past antics.
Last year, the "Do What You Want" singer arrived at the American Music Awards on a white horse and in the past, Mother Monster has sported green hair too.
Not to mention, Gaga and Katy both released their big singles, "Applause" and "Roar," last August on the same exact day.
What do you think about Gaga's jab? Tell toofab in the comment section below and click "Launch Gallery" above to see even more photos from Katy's Prismatic tour!