Yes, WALLOWED is a Scrabble word!

Letter values in Scrabble US: W 4, A 1, L 1, L 1, O 1, W 4, E 1, D 2.

Is it a valid word?

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

devote oneself entirely to something; indulge in to an immoderate degree, usually with pleasure
roll around, "pigs were wallowing in the mud"
rise up as if in waves
be ecstatic with joy
delight greatly in