Nobody did them like the Byzantines. That rump of the Roman Empire traditionally dates to Constantine* the Great (there's a nickname for you, although his given name of Gaius Flavius Valerius Aurelius Constantinus is pretty impressive just by itself). But Magnus as a nickname is boring, dating back to Alexander, and so the Byzantines soon kicked it into high gear:
Leo I "The Butcher" began as a puppet of the barbarian Goths, but ended by taking real power into his own hands. Extra credit for those who guess how he dealt with his Gothic "allies".
Leo II "The Little". Six years old, reigned for a few months. The Byzantine court has been described as a snake pit. Little Leo could tell you why.
Justinian II "The Slit-Nosed". The Byzantines loved to mutilate their enemies - castration, blinding, cutting the nose. Justinian II didn't have the ability of his namesake (Justinian the Great). Got to rock a very unusual nickname, though.
Constantine V "The Dung-Named". Nicknames don't come any better than this. You can think of him as the Richard III of the Byzantine Empire, someone who had his enemies write the history after he died.
Michael II "The Stammerer". Best known for, well, you know.
Michael III "The Drunkard". Best known for, well, you know.
And that doesn't even take us to A.D. 900 - there was another half millennium of Byzantine Autocrats to follow. What strikes me is the incredibly disrespectful tone. Constantine I Magnus would have had them all thrown to the lions or something.
This post is apropos nothing, bou can get even more on Wikipedia.
* It's odd that only 40 years after Constantine, the Emperor Valens was killed by the Barbarians at Adrianople. It was a violent age, and nor a lot of Imperators died peacefully in their beds.