Yes, PANTHER is a Scrabble word!

Letter values in Scrabble US: P 3, A 1, N 1, T 1, H 4, E 1, R 1.

Is it a valid word?

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

a large spotted feline of tropical America similar to the leopard; in some classifications considered a member of the genus Felis
a leopard in the black color phase
large American feline resembling a lion

Also: panthera onca, felis onca, mountain lion, felis concolor.