Fundamentally, a phaelros is a Snark, or perhaps a boojum. The five unmistakable marks are those of Snarks, and the fourth "is its fondness for bathing-machines / Which it constantly carries about / And believes that they add to the beauty of scenes / A sentiment open to doubt." Frequently breakfasting on five o'clock tea is also one of the marks.
"Cutting through the jungle on a golden track" is a line from "The Congo" by Vachel Lindsay, an early 20th-century poem which combines excellence of meter with utter lack of taste.
The term "transformational theory" for what is usually called the theory of evolution was coined by Harry Turtledove's alternate version of Samuel Pepys in the story "And So To Bed", reprinted in A Different Flesh.
The etymology is taken from a satirical etymology of the word "realtor", a trademark of the National Association of Realtors, who wanted a name for members of their association, as distinct from any old (real) estate agents. The idea was that "realtor" was a compound of English real and Spanish toro 'bull'.