Money is a monster, etymologically speaking. It all comes down to the Latin word monere, and even though the connection is accidental it’s probably still significant.
Monere was Latin for warn, and if you have a pre-monition you are forewarned. In the ancient world they believed that horrible beasts were omens of disasters. The idea was that just before the fall of an emperor or the loss of a great battle, centaurs, griffins and sphinxes would come out of wherever they were hiding and roam around in full view. These unnatural creatures, composed of the parts of other animals, were therefore called warnings, or monsters (monstrum, from monere).
However, if you need a warning and can’t afford a centaur, geese will do just as well. People still keep guard geese because they kick up a fearsome racket if they spot an intruder and they can also be pretty vicious. You should never say boo to a goose, not unless you’re prepared for a fight. The Romans kept guard geese on the Capitoline Hill. This came in useful when Rome was attacked by the Gauls in 390 BC, so useful in fact that the Romans put up a temple in thanksgiving. But being ungrateful sods they didn’t dedicate it to geese, they dedicated it to Juno, the goddess of warnings, or Juno Moneta.
Next door to the temple of Juno Moneta was the building where all the Roman coins were produced. In fact, the coins may have been made in part of the temple itself. Nobody is quite sure, and the sources are rather vague. What is certain is that the coin-producing building got named after the temple. It was the Moneta, and though we’ve changed all the vowels, we still call such a building a mint.
In the Moneta, they produced moneta: literally warnings. The French took the word and dropped the T so that it was already money when it arrived in English. However, our adjective monetary, meaning related to money, keeps the reference to the temple and the angry geese alive and well.
It’s only by an accident of propinquity that money is a monster. Perhaps you shouldn’t worry about it at all. Money’s not that bad. You shouldn’t be so frightened. Go on, take out that death-pledge. Sorry: mortgage.