Noun
someone with a habitually sullen or gloomy expression
Source: WordNetMr. Sourpuss Pants God I love her Nicholas " Thomas crowed. When he noticed that neither Nicholas nor Inez looked impressed by the words he added quickly "In a totally sister-in-law type fashion of course. Lynsay Sands
Moverman is generally good with his actors, but only Coogan, playing his sourpuss persona completely straight for once, finds an actual character among these wealthy, distraught relatives. Source: Internet
But I left the film thinking, “Well, this guy’s kind of a sourpuss and not very warm and friendly,” and it was kind of a disappointing experience. Source: Internet