Urchins rhymes with:
abstentions, appalachians, bastions, christians, fortune's, fortunes, hitchens, houtchens, hutchens, intentions, interventions, kitchen's, kitchens, luncheons, mansions, misfortunes, question's, questions, questions', sebastian's, suggestions, tensions
Urchins sounds like:
urgen's, urgency, urging, urgings, urokinase