Gaga disses Katy Perry's Prismatic tour look on Twitter

Lady Gaga, who has often been pitted against Katy Perry by fans, seems unhappy with the Roar hitmaker's green hair and horse prop during her Prismatic World Tour.

Lady Gaga, who has often been pitted against Katy Perry by fans, seems unhappy with the Roar hitmaker's green hair and horse prop during her Prismatic World Tour.

In what appears to be a jibe, Gaga tweeted to her over 41 million followers: "It looks like green hair and mechanical horses are the thing now."

Perry kicked off her world tour yesterday at the Odyssey Arena in Belfast, Northern Ireland, during which she rode a mechanical horse and changed into a green wig.

Interestingly, these props have featured in Gaga's own performances.