have the appearance of an egg, in fact there is no evidence of him having been deformed in any way - that's all Tudor propaganda
, immortalized by The Bard
who was writing, don't forget, for a Tudor
As for the princes in the tower, yet again there is nothing more concrete than legend to link their deaths with Richard III, and the years of violence and bloodshed - well, yes, being as it was all during the War of the Roses, to which the succession of the Tudors finally brought an end. D'uh!
As for the nursery rhyme itself, wasn't it written by Louis Carroll? In parody of indecisive politicians or something?