Synonyms of mutterer

1 Syllable
crab, bear, crank, bug, grump
2 Syllables
grouser, gripers, sourpuss, kicker, growler, crosspatch, grumbler, moaner, whiner, griper
3 Syllables
malcontent, curmudgeon, complainer, murmurer, faultfinder, bellyacher, sorehead