injaynesworld it's "The Uninvited..."

Emboldened with desire, it came in the coolness of the dusk to feed upon the unsuspecting.    With weight no more than a whisper, its delicate legs touched down on the smooth flesh where it lingered, taking in the intoxicating scent of warm, fresh blood just beneath the surface.   Its evening meal only a moment away now, it raised its head and bore down on the –

THWAP!

He who hesitates is lost.

From the prompt "Delicate" at Five Sentence Fiction.