Pop superstar Lady Gaga, took to her Twitter account to express her thoughts about another popular pop star. Gaga tweeted to her millions of followers that apparently "green hair and mechanical horses are the thing now."

Billboard reported that the tweet was sent out one day after Perry kicked off her world tour in support of her latest album PRISM.

The tour features Perry with a variety of hair colors and over the top costumes that have been designed by some of the most well known fashion designers in the industry including, Valentino and Roberto Cavalli.

USA Today added that Gaga herself has also worked with mechanical horses during her over the top entrance at the American Music Awards, when she entered on a white mechanical horse.

Gaga has recently openly announced that she will be trying to be nicer online and some are speculating that this could just be a fun tease between friends. Perry has yet to respond to the tweet.