The Collaborative International Dictionary of English v.0.48:

mudcat \mudcat\, mud cat \mud cat\n.
   A large catfish (Pylodictus olivaris, formerly Leptops
   olivaris) of the central U. S. having a flattened head and
   projecting jaw.

   Syn: flathead catfish, goujon, shovelnose catfish, spoonbill
        catfish, Pylodictus olivaris.
        [WordNet 1.5] mud-dauber

WordNet (r) 3.0 (2006):

Pylodictus olivaris
    n 1: large catfish of central United States having a flattened
         head and projecting jaw [syn: flathead catfish, mudcat,
         goujon, shovelnose catfish, spoonbill catfish,
         Pylodictus olivaris]