Orcneas are a fictional species mentioned in Beowulf.
The first etymology for 'orcneas' is that it is a portmanteau of "Orc" and "neas", meaning corpse. This would define the Orcneas as some kind of undead monsters, possibly similar to some versions of Ghouls.
However, another etymology ties it to 'orcen', another Old English world that appears to design a sea monster of some kind.
If the first interpretation is indeed correct, Orcneas are the first recorded version of Orcs in written material.