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):

mudcat
    n 1: flesh of scaleless food fish of the southern United States;
         often farmed [syn: catfish, mudcat]
    2: large catfish of central United States having a flattened
       head and projecting jaw [syn: flathead catfish, mudcat,
       goujon, shovelnose catfish, spoonbill catfish,
       Pylodictus olivaris]