YOUNG cartoon fans couldn’t believe their eyes when they spotted their underwater hero Spongebob Square-pants out and about in Southampton city centre.

The bright yellow Nickelodeon star left his Bikini Bottoms home to promote the musical version of the hit TV show – The Sponge who Could Fly – which is currently running at the city’s Mayflower theatre.

Spongebob took time out from transforming the theatre stage with his colourful friends into a scene from Jellyfish Fields in twice-daily performances, which run today and tomorrow.