"Scampi is the plural of scampo, the Italian name for the Norway lobster (Nephrops norvegicus), also known as the Dublin Bay prawn (especially in the U.K. and Ireland) and langoustine (the French name).[1] The name is used loosely both in Italy and elsewhere, though in Britain, food labelling laws define "scampi" as Nephrops norvegicus.
The fleshy tail of the Norway lobster is closer in both taste and texture to lobster and crayfish than prawn or shrimp." from wilkepedia!
I remember my dad saying that sometimes monkfish was passed off as scampi as it was cheaper.