Yes, POUTERS is a Scrabble word!

Letter values in Scrabble US: P 3, O 1, U 1, T 1, E 1, R 1, S 1.

Is it a valid word?

POUTERS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

someone with a habitually sullen or gloomy expression
one of a breed of pigeon that enlarge their crop until their breast is puffed out

Also: gloomy gus, pouter pigeon.

Not playable in Scrabble US: PICKLEPUSS.