Mutable rhymes with:
immutable, disputable, immutable, indisputable, irrefutable, disputable, immutable, indisputable, inscrutable, irrefutable, suitable, unsuitable
Mutable sounds like:
mandeville, mandible, manteufel, meatball, medfly, medieval, mehetabel, mehitabel, mehitabelle, mendivil, mindful, mindfully, montebello, montvale, montville, mothball, mouthful