Two men dominated the council of Nicea. Arius, the presbyter from Alexandria and Athanasius, its future bishop.
According to a later writer against heresy, Arius …
From elation of mind this old man swerved from the truth. He was in stature very tall, downcast in visage, with manners like a wily serpent, captivating to every guileless heart by that same crafty bearing. For, ever habited in cloke and vest, he was pleasant of address, ever persuading souls and flattering.
Constantine, when angry with him, was far from flattering about this old ascetic …
how his whole emaciated body has wasted away, is full of squalor and filth and lamentations and pallor and horror and myriad ills, and has withered frightfully; how odious and dirty in his thicket of hair; how wholly half-dead and already exhausted in its glance; how bloodless in his face and wasted under anxiety
As for Athanasius, Julian calls him
not even a man, but a common little fellow. But Gregory Nazianzen had him
angelic in appearance, more angelic in mind; calm in rebuke, persuasive in praise.
The web says that Athanasius was described as the black dwarf by his enemies. But nowhere, in book or blog, is there a source. Though catchy - it even makes Athanasius an African-American hero - the moniker seems to be an orphan.