Yes, SCREAKY is a Scrabble word!

Letter values in Scrabble US: S 1, C 3, R 1, E 1, A 1, K 5, Y 4.

Is it a valid word?

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

having a rasping or grating sound
having or making a high-pitched sound such as that made by a mouse or a rusty hinge