Bluegrass is a Marine Vice Admiral and one of the nine that took part in the siege of Egghead.
She is a short, old woman with a large amount of wrinkles and light hair arranged in a bowl cut and pigtails. She wears flowery pants, a tie, sunglasses and a pair of headphones. Like many Marines, she wears her sailing coat draped over her shoulders.

(Source: One Piece Wiki)