Bestiarus

The Bestiarus, a.k.a. Beast Men are biologically-engineered organic humanoid soldiers with superhuman strength but very limited intelligence, capable of doing little more than obeying orders. They're also completely immune to pain.

History
They were created in an alternate timeline in which the Roman Empire never fell and became a hostile interstellar nation secretly ruled by the Malevilus.

Appearances

 * Doctor Who and the Iron Legion (1979)