Chuck Liddell -- King of the Octonauts

UFC Hall of Famer Chuck Liddell fought an intense battle in L.A. this week -- no octagon ... just octonauts.

The Iceman waded through hoards of children at the Topanga Mall -- daughter in tow -- to check out "Octonauts! Live" ... a stage production based on the popular Disney show.

The kiddie crush was all smiles as they gazed at Captain Barnacle and Kwazii -- but by the look on Chuck's face, he just took one for the team.

Watch the show open and listen to the theme song ... you'll understand.