Ironicus

General Ironicus was the robot regent of an alternate Earth where Rome never fell, and the commander of its Iron Legion. Unlike his legionnairies, his head was shaped like an eagle's to honour the Imperial Eagle of Rome. He had a light on his chestplate that glowed purple when others were permitted to speak to him.

After conquering the entire galaxy, Ironicus led his Iron Legion in attacks on other dimensions, starting with a small English village. The Fourth Doctor followed them home, where Ironicus captured him and threw him to the Ectoslime. When he avoided death, the General made him a slave in the Imperial air galley. The Doctor escaped and when he did not recapture him, Ironicus was destroyed by Magog for his failure. (COMIC: Doctor Who and the Iron Legion)

Years later, when a Vortex parasite attacked the Doctor's TARDIS, it summoned images of the Doctor's enemies, including Ironicus. (COMIC: A Life of Matter and Death)

Behind the scenes
General Ironicus was notable for being the first major antagonist in the Doctor Who Magazine comic stories, although he was serving the Malevilus.