Blabera gigantea

knocker knock"er, n. 1. One who, or that which, knocks; specifically, an instrument, or kind of hammer, fastened to a door, to be used in seeking for admittance. [1913 Webster]

Shut, shut the door, good John ! fatigued, I said; Tie up the knocker; say I'm sick, I'm dead. --Pope. [1913 Webster]

2. A person strikingly handsome, beautiful, or fine; one who wins admiration; a ``stunner.'' [Slang.] [Webster 1913 Suppl.]

3. A species of large cockroach, especially {Blabera gigantea}, of semitropical America, which is able to produce a loud knocking sound. [Webster 1913 Suppl.]

4. [usually used in pl.] a woman's breast. [vulgar] [PJC]