According to NME.com, Empire of the Sun frontman Luke Steele performed the band's hits last night (July 11th 2010) wearing the fun costume, which came complete with colourful feathers.
The outfit was apparently one of a series donned by the performer during the band's lengthy set, which was backed up by a big screen showing psychedelic visuals.
Although T in the Park is now over for another year, festival fans can still watch live bands at many other forthcoming events, including Kendal Calling.
This will take place between July 30th and August 1st 2010 and visitors are encouraged to go along in superhero fancy dress and other costumes.
"Don your best glad rags for raving and misbehaving," the website encourages music fans.
This year will be the fifth anniversary of Kendal Calling.