The Collaborative International Dictionary of English v.0.48:

Hooper \Hoop"er\, n. [See 1st Hoop.]
   One who hoops casks or tubs; a cooper.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hooper \Hoop"er\, n. (Zool.) [So called from its note.]
   The European whistling, or wild, swan (Olor cygnus); --
   called also hooper swan, whooping swan, and elk. Hoopoe