The first example works if readers understand that Bernard has oodles of money. But maybe he's a mild-mannered accountant with an overdrawn account. The second leaves no room for misinterpretation.
For the next set, writers often use nouns as adjectives. It's a literary technique that draws an instant picture in readers' minds.
People use idioms like "his x is bigger than his y" because they come "pre-interpreted" by being so familiar. No one needs to add
big and
tiny to "you’re making a mountain out of a molehill" to prevent misinterpretation or make it more vivid.
It's concreteness that makes the mental picture, and
tiger is far more concrete than either
big or
behemoth. A writer makes "The dog circled the snared rabbit" more evocative by changing
dog to
Rottweiler, not by adding
big or
behemoth to
dog:
The Rottweiler circled the snared rabbit.
Or take the following pairs:
The velociraptor ran toward me.
The sasquatch stole my beer.
The behemoth velociraptor ran toward me.
The behemoth sasquatch stole my beer.
What's creating the mental images,
behemoth or
velociraptor and
sasquatch? And what did
behemoth add to either? That's why I originally suggested striking
big, not adding another adjective.
I found some examples for you showing behemoth used as an adjective.
I turned up 134 hits on "the behemoth" in the online Corpus of Contemporary American English, which is a massive database of, well, contemporary American English. The phrase "a behemoth" returned 97 hits. (The one-word "behemoth" turned up 826 and the phrases "this behemoth" and "these behemoth" will fall under Number 2 below, but examples were very few anyway.)
1. The vast majority of the examples of
the behemoth (about 85%) fit the usage I described above—i.e., behemoth is used as a stand-in for another noun.
2. About 10% of the same were appositional. Here are a few examples from the corpus:
…second place in global production, surpassed only by the behemoth Brazil.
…for law firms ranging in size from 15 lawyers to the behemoth Baker & McKenzie…
3. Another 3%-4% followed a pattern like that of Number 1, except that there was a distance between the mention of the subject and a description of its large size, so the subject is repeated (presumably to avoid ambiguity of reference), even though
behemoth could stand alone. This example is representative:
…the modern computer had been a huge block of wires and tubes about the size of an outhouse. The really powerful computers that cracked spy codes and guided inter-continental ballistic missiles were about the size of a roadside restroom along the side of the Pennsylvania Turnpike and with as much charm. These ugly contraptions jiggled punch cards and made computations. But prior to Xerox PARC the computer was bereft of colorful screens, joyous speakers, floppy discs, and all the strangely piquant terminology the engineers dreamed up. The behemoth computers of the past were used mainly by grim groups of scientists and bureaucrats. They had to schedule time on the machine. (American Spectator, 1999)
Of course, the word
computers is superfluous with
behemoth. The sentence could have begun "These behemoths of the past..." The point is that
behemoth isn't being used as the adjective
big would and could be; it's referring back to the earlier description of the computer as "huge block of wires and tubes about the size of an outhouse." Presumably
computers was plugged back in to avoid confusion with
engineers, which immediately preceded.
4. Less than 1% of the "a/the behemoth" sample fit the pattern you describe. We're talking somewhere around five hits in the entire corpus containing 826 "behemoths." The first is stage direction from the script of the film
Bamboozled:
Ext. Times Square – Night: Mantan and Cheeba gaze skyward at a behemoth billboard for their show.
Among the choices: murals, elaborately lit designs, landscapes. But the people wanted a totem pole. The behemoth sculptures, typically carved from trees by native peoples to illustrate ancient legends, watch over lands in Alaska and the Pacific Northwest. (Washington Post)
Not exactly inspiring.
Behemoth sculptures adds abstraction to abstraction, evoking some large amorphous thing.
The massive wooden sculptures/tree carvings/artworks would have evoked a stronger image.
So, I modify my original statement to say I've
rarely seen
behemoth used as a premodifier. And when I have, it wasn't particularly pretty.