spadefoot

from WordNet (r) 3.0 (2006)

spadefoot
    n 1: a burrowing toad of the northern hemisphere with a horny
         spade-like projection on each hind foot [syn: {spadefoot},
         {spadefoot toad}]

from The Collaborative International Dictionary of English v.0.48

Spadefoot \Spade"foot`\ (sp[=a]d"f[oo^]t`), n. (Zool.)
   Any species of burrowing toads of the genus {Scaphiopus},
   esp. {Scaphiopus Holbrookii}, of the Eastern United States;
   -- called also {spade toad}.
   [1913 Webster]