Yes, WREN is a Scrabble word!

Letter values in Scrabble US: W 4, R 1, E 1, N 1.

Is it a valid word?

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

English architect who designed more than fifty London churches (1632-1723)
any of several small active brown birds of the northern hemisphere with short upright tails; they feed on insects

Also: sir christopher wren, jenny wren.