Katy Perry will be thinking of her childhood dreams when she performs at the Super Bowl halftime show.

The 'Roar' hitmaker is set to take to the stage halfway through the American football game between the Seattle Seahawks and the New England Patriots at the University of Phoenix later today (01.02.15), and has dedicated the performance to her younger self.

She tweeted: ''Today is for this girl. She had the dream, always believed in herself & her worth. Today she is the one smiling.''

The 30-year-old performer - whose parents are both Pentecostal pastors - added she will be celebrating ''the day that the Lord has made''.

She wrote: ''Today is the day that the Lord has made! I will rejoice and be glad in it!''

Last month, Katy revealed she would be joined on stage by 'Fly Away' singer Lenny Kravitz, while rapper Missy Elliott is also rumoured to be performing with the star as she sings a medley of her greatest hits.

Teasing further details of the 12-and-a-half-minute performance, she told viewers to expect numerous costumes as well as live animals.

Speaking at the NFL press conference at the Phoenix Convention Center, she hinted: ''I think I'm the only person to ever do a half time show who brings a lion and sharks to the show.

''It's going to be wild out there. I'm creating three or four different worlds.

''My entrance and exit are spectacular, the costumes are great, the music, I have a lot of songs to cover so there will be some medley of sorts.''