I would interpret the phrase as a derivation of to feed the beast. The earliest Google Books results for this phrase refer to the literal feeding of animals, but by 1900 we have uses such as
They perfectly understand the utility of “feeding the beast” with a nice dinner to keep him good-tempered
in reference to keeping a potentially beastly person happy, or of subduing the beast within, representing the savage instincts of humanity that ration and civilization keep in check. That phrase may have originated in translations of Plato's Republic:
I mean those which are awake when the reasoning and human and ruling power is asleep; then the wild beast within us, gorged with meat or drink, starts up and having shaken off sleep, goes forth to satisfy his desires; and there is no conceivable folly or crime … which at such a time, when he has parted company with all shame and sense, a man may not be ready to commit.
To feed the beast, then, is to surrender to something wild and uncontrollable. Perhaps you feed it just enough to stay quiet, hoping to tame it— but perhaps you indulge it, to make it stronger and more vicious (not unlike adding fuel to the fire).
You see results relating to China because the dragon is a synecdoche for China, which is being viewed as a metaphorical beast in some way (after all, feeding the panda or feeding the crane is not nearly as threatening). Similarly, you see uses like feed the bear for indulging Russia. To starve the beast is to end one's obeisance to the beast, enduring the consequences, in hopes of being freed of it; for fiscal conservatives, for example, to starve the beast is to deprive the government of revenue under the theory that it would force the government to reduce spending.
Chasing the dragon similarly uses a dragon to represent China, but is an unrelated phrase. It may refer to competing with China, or it may mean an impossible pursuit, or something else; it is hard to say without context.
odd pants, in that they were not part of a suit (coat pants with or without vest)
Growing Up: Childhood in English Canada from the Great War to the Age
of Television (Themes in Canadian Social History)Aug 16, 1997 by Neil
Sutherland google books
"For Hugh Palmer's 'Sunday best,' his father 'bought me a pair of black
Oxfords to go with my blue serge suit. How I hated that suit. The
short trousers, or "stovepipes," were unlined, and the serge was a
particularly rough sort - no doubt designed to cause maximum chafing
just above a boy's knees.'11 In Cedar Cottage, one man explained,
boys' Sunday outfits 'weren't suits, you know ... odd pants and some
gloves, a shirt or something ... but they weren't too fancy clothes at
that..."
It appears that after the great war, clothing factories sprung up specializing in just [odd] pants, to the chagrin of complete suit manufacturers.
"One of the most popular styles of the odd pants was the very loose
white flannel trousers. They were worn by men who were extremely
class conscious and wanted to visually remove themselves from the less
financially fortunate. In The Great Gatsby, Nick describes that for
the lawn party he “dressed up in white flannels....” The two other
kinds of odd pants worn by men were the trousers called Oxford Bags
and knickers." Google books: Fashion in the Time of the Great Gatsby
And now ... just pants. Whereas men would own many suits, they now own a suit or 2, 5 or so sport jackets and numerous pants with odd and varied patterns, colors etc. And ... definitely a number of pair of khakis.
Best Answer
This goes very far back in time indeed - right to the Indo-European era. There is a book that talks about the common features of Indo-European speech and poetry - still to be seen in kindred languages such as Greek, Sanskrit, Old Irish, Latin, English, etc.
It's titled How to kill a dragon, using the dragon as one theme that was common to the poetries of nations that inherited this common culture.
Of course, this doesn't directly answer your question, but this question, interesting as it is, is the topic of a book or two, like the one I recommend.