Fatter rhymes with:
mcfatter, mcphatter, antimatter, attar, batter, blatter, chatter, chitterchatter, clatter, flatter, hatter, latter, matter, mcfatter, mcphatter, natter, patter, platter, sater, satter, scatter, schlatter, shatter, slatter, smatter, spatter, splatter, tatar, tatter, vanatter, vannater, vannatter, vatter
Fatter sounds like:
fader, father, fatheree, feather, feathery, feature, fedder, feder, federer, fedor, fedora, feeder, feodor, feodora, fetrow, fetter, fidder, fidora, fitter, fitterer, fittro, fodder, fodera, fodor, footer, footware, footwear, futher, future, fyodor