curmudgeon

Example:He was an old grump who would always complain about the weather.

Definition:An elderly person who is frequently in a bad mood and quick to criticize or complain.

Example:The sourpuss wouldn't even greet me as I passed by.

Definition:A person who is sullen, glum, and often uncooperative, as from a brooding sense of personal injury.

Example:The grouch was seen grumbling to himself throughout the meeting.

Definition:A person who is usually or habitually in a bad mood; a grumbler.