THE MULE: Less is known of "The Mule" than of any character of comparable signifigance to Galactic history. His real name is unknown; his early life mere conjecture. Even the period of his greatest renown is known to us chiefly through the eyes of his antagonists and, principally, through those of a young bride.. It was after the fall of the First Foundation that the constructive aspects of the Mule's regime took shape. After the definitive break-up of the first Galactic Empire, it was he who first presented history with a unified volume of space truly imperial in scope. The earlier commercial empire of the fallen Foundation had been diverse and loosely knit, despite the impalpable backing of the predictions of Psychohistory. It was not to be compared with the tightly controlled Union of Worlds under the Mule, particularly during the era of the so-called Search. (Bayta Darell)...
The Mule was a powerful mentalic mutant, warlord, and conqueror who posed the greatest threat to the Seldon Plan. His acute telepathic ability to modify the emotions of human beings derailed one of the basic assumptions of Hari Seldon's psychohistory - that, in general, the responses of human populations to given stimuli will remain the same.
The Mule was born on the mentalic planet Gaia within Sayshell Sector, where he was regarded as a criminal for his willingness to use his mental powers to manipulate people. By some means he managed to escape the planet at a young age and use the innate powers of its inhabitants against the Galaxy.
Motivated by awareness of his abnormal appearance and hatred against the galaxy, the Mule used his extensive powers to rise to power: first conquering a pirate's asteroid base, an industrialist later gave him control of a planet. From there he managed to take over the planet Kalgan by converting the then warlord of Kalgan. This gave him the possibility of conquering the First Foundation, but he needed allies for this, so he decided to disguise himself as a clown, claiming to be his own jester, in order to seek the agents the Foundation would sent to investigate him. This allowed him to meet Han Pritcher, but the first to encounter him were Toran and Bayta Darell, whom he ended joining in their travels. This, at the same time, allowed him to have Kalgan declare war on the First Foundation, conquering both it and the Independent Traders' planets. His attempts to find the Second Foundation through manipulation of Ebling Mis, though, ended up being stymied in the last second thanks to Bayta, who had realized who he was and killed Mis before he could speak up. The Mule ended up leaving, allowing the Darells to go untouched on the basis of their friendship.
During the following years, the Mule continued to use his power to sweep aside the last remnants of the Galactic Empire centered around Neotrantor and forging the Union of Worlds, styling himself First Citizen of the Union. However, his plans to create a new Empire were kept in check by his fear of the Second Foundation, which led him to organizing multiple expeditions to seek it. The sixth expedition, led by Bail Channis (who turns out to be a Second Foundation agent) appears to be successful, but in fact it is all a trap created by the First Speaker of the Second Foundation, who defeats the Mule and alters his mind, making end his quest and spend the last years of his life as a benevolent dictator, eventually dying a premature death resulting from his mutation.
His name is one he gives to himself, a reference to his genetic sterility. For this reason his empire does not last long after his death.
Physically, The Mule was considered a freak by most people who gazed upon him. His nose was incredibly long, sticking out over three inches from his face. The flesh of the rest of the Mule's face seems stretched across his skull. The Mule's body was spindly and gangly: he weighed only 100 to 120 pounds (45 to 54 kg), stretched out across a 5'8" frame. Thus his joints, such as elbows, seemed to jut out from his diminutive musculature. The Mule's meagerness was glandular and could not be compensated for. Further, the Mule's limbs met at awkward angles, giving the general impression of a scarecrow assembled poorly. It was said that one could not look at the Mule without derision. The only aspect of the Mule which was not blatantly farcical were his eyes, which were described as deep brown and perpetually sad.
The Clown (Magnifico Giganticus)
The Mule disguised himself as the Clown when he met Bayta and Toran Darell. This was his way of taking over the First Foundation. He manipulates the constables and guards into believing he is indeed the escaped 'clown', but at this early stage, neither Toran or Bayta are aware of his psychomanipulative powers.
In the process of negotiations, the Clown/Mule is given a Visi-Sonor, by Ebling Mis with which to amuse himself. He exclaims to Bayta that in his rush to 'flee' the Mule, that he had left his behind. He then offers to play the instrument for Bayta whom he calls "My Lady". In his hands the Visi Sonor not only creates exquisite sounds, but colors, shapes and with the Mule's mental ability, emotion. The Mule disguised as the clown uses his concerts and fame to brain wash everyone.