Carnival's rhymes with:
carnivals, carnivals, carnivals, carnivals, carnivals, festivals, approvals, archrivals, arrivals, carnivals, crovls, daredevils, devil's, devils, devils', evils, festival's, festivals, hovels, intervals, level's, levels, marvel's, marvels, nevels, nevils, novel's, novels, removals, revels, revivals, rival's, rivals, rivals', shovels, sivils, swivels, travels, unravels, upheavals, weevils
Carnival's sounds like:
carnivals, chernobyl's, crumbles