Cuttle

1. A knife.
   

1. (Zoöl.) A cephalopod of the genus Sepia, having an internal shell, large eyes, and ten arms furnished with denticulated suckers, by means of which it secures its prey. The name is sometimes applied to dibranchiate cephalopods generally.
2. A foul-mouthed fellow.

It has an ink bag, opening into the siphon, from which, when pursued, it throws out a dark liquid that clouds the water, enabling it to escape observation.