Thornback :: Thornback (n.) A European skate (Raia clavata) having thornlike spines on its back.
Thornback :: Thornback (n.) The large European spider crab or king crab (Maia squinado).
Thornbill :: Thornbill (n.) Any one of several species of small, brilliantly colored American birds of the genus Rhamphomicron. They have a long, slender, sharp bill, and feed upon honey, insects, and the juice of the sugar cane..
Thornbird :: Thornbird (n.) A small South American bird (Anumbius anumbii) allied to the ovenbirds of the genus Furnarius). It builds a very large and complex nest of twigs and thorns in a bush or tree.